Testing innovative strategies to reduce the social gradient in the uptake of bowel cancer screening: a programme of four qualitatively enhanced randomised controlled trials

Article history

The research reported in this issue of the journal was funded by PGfAR as project number RP-PG-0609-10106. The contractual start date was in March 2011. The final report began editorial review in March 2015 and was accepted for publication in May 2016. As the funder, the PGfAR programme agreed the research questions and study designs in advance with the investigators. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The PGfAR editors and production house have tried to ensure the accuracy of the authors’ report and would like to thank the reviewers for their constructive comments on the final report document. However, they do not accept liability for damages or losses arising from material published in this report.

Declared competing interests of authors

none

Disclaimers

this report contains transcripts of interviews conducted in the course of the research and contains language that may offend some readers.

Copyright statement

© Queen’s Printer and Controller of HMSO 2017. This work was produced by Raine et al. under the terms of a commissioning contract issued by the Secretary of State for Health. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising. Applications for commercial reproduction should be addressed to: NIHR Journals Library, National Institute for Health Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK.

Background

Aim and objectives

Our aim was to reduce socioeconomic inequalities in bowel cancer screening uptake in England without compromising uptake in any socioeconomic group.

In order to achieve this, we set out the following objectives:

1. to explore psychosocial and cultural determinants of low uptake of the gFOBt

2. to develop and test four theoretically based interventions to reduce the socioeconomic gradient in screening uptake

3. to undertake RCTs to evaluate the effectiveness and cost-effectiveness of each intervention within the NHS BCSP.

ASCEND workstreams

Our programme was divided into three workstreams to address our objectives.

Patient and public involvement and engagement

Our first ASCEND patient representative, Mr Fuller, contributed expertise from a patient perspective during the drafting of the original application, particularly regarding workstream 2 and the planning of the development of the interventions. Unfortunately, Mr Fuller was unable to offer further support following the grant being awarded owing to ill health. We recruited another patient representative (Mr Band), who reviewed some of the ASCEND development work (namely the narrative leaflet) and attended our Advisory Group meeting prior to the start of the national trials. In addition, we worked with individuals from a number of charity and community groups and organisations, Primary Care Research Networks and faith settings who helped us to identify specific groups of people to take part in the development stages of the study (see Chapters 3–6 for further details).

The research team also undertook engagement activities, presenting information about the study at conferences and to other groups, as well as publishing peer-reviewed papers of the study findings.

Introduction

The NHS BCSP, established in England in 2006, offers bowel cancer screening every 3 years to adults aged 60–69 years (inclusive) using a gFOBt kit that is completed at home. Between 2008 and 2014, the programme was gradually extended to include subjects aged 70–74 years. Primary endoscopy screening is now being added to the programme following the UK Flexible Sigmoidoscopy Screening Trial,38 with a single flexible sigmoidoscopy (FS) offered at 55 years. FS screening started after the completion of the ASCEND programme.

Bowel Cancer Screening Programme hubs

Five NHS BCSP hubs provide the ‘call and recall’ service for the screening programme in England: London, Southern England, Eastern England, Midlands and North West England and North East England (Figure 1). This involves the use of the Bowel Cancer Screening System (BCSS) database to invite the eligible population as their screening becomes due. To support this process, all hubs offer a helpline service to provide advice and a laboratory service to test all returned kits.

FIGURE 1.

Map of England showing the five Bowel Cancer Screening hubs.

Screening pathway

A detailed diagram of the NHS BCSP screening pathway is included in Appendix 1. In brief, each hub sends an initial invitation (‘pre-invitation’) pack to all eligible people in their area describing the programme and its objectives. The pre-invitation pack contains a letter (see the S1 letter, Appendix 2) and ‘The Facts’ booklet (see Appendix 3). A week later, the hub sends out the gFOBt kit (Figure 2) with a formal invitation letter (referred to as the S9 letter; see Appendix 4) and a leaflet explaining how to do the test (the screening instruction test kit leaflet; see Appendix 5). The test kit includes the gFOBt card, cardboard spatulas for sample collection and a reply-paid envelope in which to return the test for analysis at the NHS BCSP hub laboratory. There are three flaps on the test kit, each of which covers two sample application ‘windows’. Two tiny samples are taken from a bowel motion and spread onto each of the two windows using the cardboard spatulas provided. The flap is then sealed and dated and the process is repeated for the second and third bowel motions (using the windows under the second and third flaps, respectively). Once all six windows have been used, the test kit is returned to the laboratory for analysis. The test kit must be received by the hubs within 21 days (subjects are told 14 days, to allow time for return postage) of the first sample being taken to ensure that a valid test result can be obtained. The hubs process the completed gFOBt kits in their laboratories and send out result letters to participants within 2 weeks of receiving a completed test kit. If a test kit has not been returned within 4 weeks of the date it was sent, the hub sends out a reminder letter (referred to as the S10 letter; see Appendix 6).

FIGURE 2.

The gFOBt kit.

The possible test results for kit 1 are described in Table 1. Up to three test kits may be needed to reach a ‘definitive’ test result of ‘normal’ or ‘abnormal’. If none of the six windows is positive for blood in the faecal sample on the first test kit, the test result is normal and the participant will be invited to be screened again in 2 years’ time (if they remain within the eligible age group). If five or six windows test positive on their first kit, the result of the screening test is abnormal and the participant is offered an appointment with a specialist screening practitioner (SSP). If between one and four windows are positive on their first kit, the result of that test is ‘unclear’ and the participant will be asked to repeat the test. If one or more windows test positive on a second test kit the definitive test result is abnormal (‘weak positive’) and the participant is referred to a SSP. If no windows are positive on the second test kit, a third test kit is sent and any positive windows result in referral to SSP. Participants will be asked to repeat the test if a test was completed incorrectly (‘spoilt’) or there was a problem in the laboratory during processing (‘technical failure’).

General practitioners are not directly involved in the delivery of the NHS BCSP but the practice receives written (or electronic) notification of the screening results for their patients including a notification of a SSP appointment and colonoscopy outcome. Practices are also informed about subjects who have not taken part in screening.

Each NHS BCSP hub provides a freephone helpline service. Helpline staff are not medically trained but have received training on common diseases of the bowel and have a sound knowledge of the screening pathway. Helpline staff provide guidance on how to complete the test kit, are able to answer queries about the appropriateness of screening (complex clinical queries are passed to the hub management team) and can reschedule clinical NHS BCSP appointments etc.

Individuals who receive an abnormal test result are invited to attend an appointment with a SSP at a local screening centre. The SSP will discuss a follow-up investigation and arrange a colonoscopy, if appropriate. There are 60 screening centres across England (between 6 and 18 per hub area). Colonoscopy is an invasive procedure that involves passing a thin, flexible tube with a tiny camera attached through the rectum and around the bowel to look directly at the lining of the large bowel. Preparation for colonoscopy requires the subject to use a self-administered laxative for thorough bowel cleansing and a sedative is sometimes used during the procedure. If polyps are found in the bowel, most can be removed painlessly using a wire loop passed down the colonoscope tube. These tissue samples are then checked for any abnormal cells that might be cancerous. On average, for every 10 people undergoing a colonoscopy following an abnormal gFOBt kit result, five will have a normal result (or non-cancerous/non-polyp abnormality), four will have a polyp (which, if removed, may prevent cancer developing) and one will have cancer.

Screening ‘episodes’

For screening participants, a screening episode refers to the period of time from when an S1 pre-invitation letter is sent to an eligible individual to when they receive a definitive normal test result or to an outcome from colonoscopy for those referred for further investigation. If a subject has not responded by returning a test kit or contacting the hub to opt out of screening within 18 weeks of the initial pre-invitation letter being sent out, the screening episode is closed and the subject will receive another invitation to take part in screening 2 years after their previous screening due date, if they are still within the age group to be screened (60–74 years).

Subjects are first invited to take part in screening within approximately 6 weeks following their 60th birthday and may then be invited to take part in screening every 2 years, depending on test results, outcomes from any follow-up and age, and regardless of whether or not they have taken part in the past. Individuals aged ≥ 75 years can request a test kit every 2 years from the NHS BCSP if they wish to be screened.

The first time an individual is invited to be screened is referred to as the prevalent screening episode (‘prevalent previous non-responders’ refers to subjects invited to be screened at least once previously but who have not participated). ‘Incident’ screening is the term used for episodes of repeat screening (i.e. in the case of subjects who have participated in screening previously).

Initiatives to promote the Bowel Cancer Screening Programme

A number of organisations promote awareness of the NHS BCSP. Clinical Commissioning Groups [and formerly primary care trusts (PCTs)] fund a variety of local initiatives to promote uptake of screening, including promotion of screening at flu vaccination clinics, placing posters in general practices and providing information stands at health fairs, general practices, libraries, conferences and hospital open days, as well as various GPE strategies and targeted recruitment of individuals not taking part in screening. The Southern Hub is piloting a new approach to increase participation by working in partnership with general practices and sending a second reminder letter using the surgery letter head and a local GP signature. The National Awareness and Early Diagnosis Initiative also co-ordinates and provides support to activities that promote the earlier diagnosis of several cancer types in England, including breast, bowel and lung cancer.

Several charities, including Beating Bowel Cancer (Teddington, UK), Bowel Cancer UK (London, UK) and Cancer Research UK (London, UK), also fund campaigns to promote uptake of bowel cancer screening.

Introduction

In workstream 1 we explored the psychosocial and cultural determinants of low uptake of gFOBt. In this chapter, we describe how we carried out focus groups with men and women from different socioeconomic backgrounds in London and South Yorkshire in order to identify specific barriers to screening uptake.

Uptake of bowel cancer screening in South Asian communities is particularly low, at 31.9% in the Muslim community, 34.6% in the Sikh community and 43.7% in the Hindu community, compared with average uptake across the whole population (53%). 12,40–42 Low uptake of colorectal cancer (CRC) screening in the UK has continued to be identified in areas with higher ethnic diversity,5,12 and within all South Asian religiolinguistic groups even when age, deprivation and gender are adjusted for. 40,43 We therefore also explored culturally specific barriers to uptake in South Asian communities to identify additional appropriate methods which could be specifically targeted at minority ethnic groups who speak English. To do this, we carried out interviews with 16 participants acting as ‘key informants’ on behalf of their communities. This interview study is described in Chapter 4.

The current research evidence in this area includes qualitative explorations of attitudes towards bowel cancer screening. Most of these studies were conducted in the USA or report insights relating to a range of screening methods including gFOBt, colonoscopy and FS. 44–47 This limits their applicability to the UK NHS BCSP. The sparse literature focusing on gFOBt33,42,48–52 has identified reasons for non-uptake including feeling healthy and having no bowel symptoms, fear of the outcome of screening and ‘not wanting to know’, which was often linked to doubts about the value of screening to detect health problems. Difficulties in understanding the kit instructions, concerns about hygiene and storage of the kit, avoiding or delaying decision-making, intention to take part but failure to do so owing to practicalities, and the preference for a doctor to do such tests have also been identified as reasons for not completing screening. 33,42,50,51,53 An association between being invited to be screened and entry into ‘old age’ has also been identified as a factor influencing the decision to be screened. 52 The need to deal with faeces to complete the test has not been reported as a major barrier to participation in screening, with previous studies42 reporting that the majority of respondents have not tended to express disgust or reluctance to handle faecal matter. However, the material realities of the gFOBt do constitute a barrier to participation for some individuals. 42,45,50

Few qualitative studies have focused on the English NHS BCSP. Two studies carried out during the NHS BCSP pilot phase explored the acceptability of gFOBt with individuals who had not yet been invited to take part in the NHS BCSP. 42,51 Findings from these studies were therefore based on participants’ hypothetical commentaries regarding the acceptability of the programme design and screening process. Recruitment of participants with actual experience of being invited to the NHS BCSP is limited to three qualitative studies. In one, the majority of the participants had completed the gFOBt kit50 and the other two report on small samples, each restricted to one geographical area in England. 33,52 The experiences of individuals who have been invited to the NHS BCSP and have not taken part, who might be expected to offer the richest insights into screening non-uptake, have been largely absent from the research literature to date. Furthermore, the beliefs of individuals who do not take part in one round of screening but subsequently take part in another round is limited to one recent study which describes how beliefs, awareness and intention change over time. 33 These participants are of particular interest because of their potential to explain why people make different uptake decisions on separate screening rounds.

Finally, research exploring the views and experiences of ethnic minority participants to an invitation to the NHS BCSP is, with the exception of Szczepura,42 extremely limited, despite ethnic diversity in the UK population and variation in screening uptake linked to ethnicity. 12,40,54

A single study on FS screening (an invasive form of bowel cancer screening not routinely used in the NHS BCSP at the time this research was conducted) identified specific cultural barriers associated with the threats to masculinity in African Caribbean men. 55 However, it is not known whether such barriers are also present in relation to gFOBt or if there are any culturally specific issues related to gFOBt screening among African Caribbean women.

The research presented here therefore adds to the literature in two important respects. First, we explored non-uptake decisions in a socially and ethnically diverse sample of individuals with experience of non-uptake within the English NHS BCSP. Second, we included participants who made different uptake decisions on separate screening rounds. This allowed us to identify ‘tipping points’, that is, the factors that changed an individual’s mind about screening.

Aims

1. To explore psychosocial determinants of bowel cancer screening uptake with an attention to the possible differences between socioeconomic and ethnic groups.

2. To explore the reasons for participating in screening following non-participation in a previous screening round.

Objective

To understand determinants of initial non-uptake and reasons for subsequent participation in gFOBt screening using focus groups, homogeneous with respect to gender, SECs and ethnicity.

Methods

Ethics

The study received ethics approval from South East London research ethics committee five (reference 11/H0805/7) and NHS trust research governance was obtained at the relevant sites. Written informed consent was obtained from all participants.

Patient and public involvement and engagement

We collaborated with community groups to recruit potential focus group participants. In Doncaster we worked with three community centres (contact details were provided by ContinYou colleagues), an indoor bowls centre and a men’s 60+ social group, supported by AgeUK (found through our own research). ContinYou also put us in touch with three community centres in London. In addition, we approached an over-50s exercise group at a London sports centre, a ‘men’s shed’ group and an over-50s library group, inviting them to take part in our research. AgeUK worked with us in London, for example, inviting us to a black and minority ethnic elders meeting in London, where we made a contact who arranged a focus group with Caribbean women based at a church exercise group in North London. All of these groups were extremely willing to help but, unfortunately, we often found that many of the people available were outside the age bracket we were seeking and, if they were of screening age, they tended to be positive about screening.

Following the publication of our results in the British Journal of Cancer,32 we produced an information sheet summarising the findings and posted this to all participants who expressed an interest in receiving them.

Data management and analysis

After each focus group, the audio-recording was sent securely to a third-party transcription agency and transcribed verbatim. The research team members who led each focus group (CP or MT) then checked the transcripts for accuracy in comparison with the audio-recordings and written notes and removed any identifying information. Transcripts were not returned to participants for comment or correction. Audio-recordings and electronic transcripts were saved on a secure password-protected drive. Paper transcripts and written notes were kept in locked office cabinets.

An inductive analytical approach was used to generate themes from the data. During the first stage of analysis, two members of the research team (CP and MT) working with hard copies of the data descriptively coded each transcript as it was generated; this was done in a grounded way, meaning that all data were closely and repeatedly read and coded without reference to ‘a priori’ topics linked to the research questions of interest to the study. During this initial open and grounded coding stage, the researchers would meet regularly to discuss the emerging codes and areas of commonality and difference between each researcher’s codes. As further transcripts were coded, the researchers coidentified patterns of repeating or similar codes across the data, which they clustered into early themes and wrote brief descriptive summaries of each. There was little disagreement between the researchers when clustering codes into early themes; however, the labelling and descriptions of early themes were discussed and revised collaboratively to agree on wording that was acceptable to both researchers.

Following grounded coding of the first eight focus group transcripts, these data and associated codes and preliminary themes were entered in to NVivo version 10 (QSR International, Warrington, UK) to increase data manageability and retrieval. The researchers had regular meetings in which early themes and their associated data extracts were printed out and discussed with reference to the data extracts to within the theme and against other early themes. During these discussions, themes were refined and the changes saved within NVivo. The associated summaries of the early themes were also extended and refined and saved within Microsoft Office^® 2010 (Microsoft Corporation, Redmond, WA, USA) documents with the associated data extracts coded within that theme. At this point, the researchers considered all thematic categories and began to jointly identify the thematic areas that were emerging to be most relevant to the research questions of interest. The researchers presented the developing themes and associated data extracts to the wider research team at frequent intervals in order to inform, when possible, the content and development of the gist, narrative, GP and ER letter interventions.

Following the identification of key themes, the researchers created a framework grid in which the data extracts illustrating each emerging key theme were inserted alongside the focus group number and participant from which they had originated. This allowed the researchers to easily identify the individual focus groups from which data extracts had been categorised and, importantly, allowed the researchers to identify the ‘spread’ of emerging key themes across the eight focus groups. This revealed that the coidentified key themes were present and repeated across the majority of the focus groups.

As the remaining 10 focus groups were completed and transcribed, the data were coded by the same two researchers using the thematic framework developed during analysis of the first eight groups. The researchers also undertook some open coding for which data did not fit into a pre-developed theme. The themes were revised and refined with reference to these data when necessary, as were the thematic summaries. The thematic framework was barely changed with the addition of the second phase of focus group data indicating that the key themes relating to gFOBt non-uptake had reached saturation. However, analysis of these data did lead to the generation of new codes relating to ‘tipping points’ to screening, which were clustered into themes following the same processes described above and saved as word documents comprising a descriptive summary below which all the relevant data extracts were saved. The identification of these new themes was due to the inclusion of participants in the second phase of focus groups who had changed from non-uptake to uptake of gFOBt on a subsequent invitation to the NHS BCSP. The framework grid of key themes and illustrative data extracts was extended with data extracts and the new ‘tipping point’ themes from focus groups 9–18. Our analysis produced detailed summaries of the key themes accompanied by extensive illustrative empirical material, which were written up for publication.

Once all focus group data had been analysed, the researchers undertook additional comparative analyses to determine if themes could be identified that were specific to focus groups clustered by gender, occupational background, ethnicity or geographical location. Only one such theme was identified, which related to the way in which participants with ‘professional occupations’ described ‘delay’ as a key component of their gFOBt non-uptake. However, in the vast majority, the key themes relating to gFOBt non-uptake were present and repeated in each focus group. The key theme relating to ‘tipping points’ to screening was present and repeated across groups 9–18 because these were the groups containing participants with experience of taking part in a subsequent screening round.

Throughout the analytical process, emerging themes and their associated illustrative quotations continued to be presented to the wider research team for discussion and to inform intervention development. The key themes were also presented to study coapplicants present at the ASCEND steering group.

Results

Participant characteristics

In the first wave of recruitment, 2560 participants were invited (1280 from areas served by each hub). We anticipated a 2.5% response rate, which would equate to approximately 32 responders in each hub area. We estimated that we should be able to convene two focus groups of between 6 and 12 participants in both areas with this level of response. Our response rate was actually nearer 5% and, therefore, we were able to convene four focus groups in each area. In the second wave of recruitment (and in order to achieve at least a further six focus groups), the hubs posted invitations to 2540 individuals (1270 from areas served by each hub).

As a result of these two separate waves of recruitment via the NHS BCSP, we received 243 completed consent forms from 129 men and 114 women. A total of 111 individuals subsequently attended a focus group. We intended to run 14 focus groups but were able to hold 16 owing to higher than anticipated response rates. We paid attention to ensuring the sample included a balance of men (n = 60) and women (n = 51), and individuals with reported professional (n = 61) and non-professional (n = 50) occupational backgrounds (see Table 2). Reported professional occupations included teacher, local government officer, solicitor, civil servant, nurse, dentist, journalist, artist and social worker, and non-professional occupations included sales assistant, cook, cleaner, carer, builder, miner, driver, waitress, postman and carpenter.

Recruitment using a market research company resulted in one focus group of seven primarily African Caribbean men and the approach by the research team to the north London church exercise group resulted in one focus group of 10 primarily African Caribbean women. In common with the purposively sampled focus groups, the two opportunistically recruited focus groups comprising individuals of African Caribbean origin also included participants who had and had not taken part in bowel cancer screening; however, these two groups were not organised with reference to occupational background.

In total, 18 focus groups were held with a total of 128 participants (Figure 3). The majority of participants recalled receiving invitation(s) and gFOBt kit(s) from the NHS BCSP. One hundred participants reported gFOBt non-uptake on at least one occasion, of whom 31 went on to complete the gFOBt kit when they were invited to take part in a subsequent screening round. Nine participants had not completed the gFOBt owing to ‘alternative uptake’ of bowel cancer screening, such as colonoscopy, endoscopy or gFOBt kit completion in primary or private care. Our comparative analyses found high consistency in accounts for non-uptake regardless of gender, ethnicity, occupational background or geographical location.

FIGURE 3.

Recruitment of focus group participants.

Themes

We present our findings as a series of six themes described below. To ensure anonymity, the identity of participants who provided the selected direct quotations is limited to focus group attended (i.e. FG01) and assigned participant number within this group (e.g. P1).

Discussion

Our analysis of participants’ accounts has identified key themes that inform understanding of why non-uptake of bowel cancer screening occurs. Furthermore, our comparative analysis of focus group data by area (inner-city London, Doncaster and Barnsley), gender, occupational background and ethnicity found few differences in the ways in which participants accounted for non-uptake. In common with previous studies,45,50,51 we have identified the threats to hygiene posed by completion of a gFOBt kit. However, our analysis extends the understanding of the problems posed by faeces with the concept of ‘social pollution’. Taboos surrounding interactions with faeces65,66 mean that completion of a gFOBt kit may be considered ‘improper’ in addition to unpleasant. The troubling nature of faeces is therefore a key element in participants’ non-uptake of the gFOBt. In addition, we found that the requirement to undertake the gFOBt kit oneself and in one’s own home represented a detachment from familiar medical settings and roles, which, in turn, impersonalised or devalued screening as a valid health endeavour. The prospect of self-testing at home was for some unsettling rather than facilitating of uptake. This finding is unreported elsewhere in the literature.

Ambivalence about the value and benefit of the knowledge offered by screening, and of medical intervention more generally, has been identified previously. 47,50,51 Participants confidently articulated the negative implications of participation in screening and emphasised the benefits of not being in possession of such knowledge. Non-uptake was therefore presented as having protective and beneficial effects. In addition, we found that participants described delay and non-uptake of the gFOBt kit owing to its prolonged and complex nature, and identified misconceptions about correct test completion that may contribute to perceptions of complexity. We further identified the well-documented misconception that having no symptoms meant that screening was not needed. 44,47,49,50 Finally, we have identified the influence of talking with others as a tipping point to uptake of screening. We suggest that it is through talk that completion of a gFOBt kit may be ‘reformed’ as a normal and culturally appropriate activity, and that concerns about its unexpected and potentially inappropriate aspects may be alleviated.

Conclusion/summary

Our focus group study provided insights into why people do not take part in bowel cancer screening and why people participate in one round of screening but not in another. The findings from this study were used specifically to inform the design of ASCEND intervention 4, described in Chapter 8. Although not intended to be used directly to inform the design of intervention 2 and 3, it emerged from the focus groups that learning of other people’s views and screening experiences could act as a decision ‘tipping point’ and that input from a GP would influence people’s intention to take part in screening, further emphasising the potential impact of these interventions.

Introduction

In workstream 1 we explored the psychosocial and cultural determinants of low uptake of the gFOBt. In this chapter, we describe how we undertook interviews with ‘key informants’ representing South Asian Muslim, Sikh and Hindu faith communities in London, in order to explore culturally specific barriers to uptake in South Asian communities and to identify appropriate strategies to increase uptake which could be specifically targeted for minority ethnic groups who speak English.

Uptake overall within the NHS BCSP is about 56%, but this figure masks much lower rates in South Asian communities, which vary from 31.9% in the Muslim community, through 34.6% in the Sikh community to 43.7% in the Hindu community, than in ‘non-Asians’. 40–42 South Asian minority ethnic communities (comprising Indian, Pakistani and Bangladeshi groups) make up 7.5% of the population of England and Wales. 68,69 Low uptake of bowel cancer screening in the UK has continued to be identified in areas with higher ethnic diversity5,12,54 and within all South Asian religiolinguistic groups, even when age, deprivation and gender are adjusted for. 40,43 A study of participation in bowel cancer screening using FS (an internal examination undertaken by a medical professional) similarly found lower uptake by South Asian participants after socioeconomic status had been controlled for. 70 Inequalities are also present in the longer-established UK breast and cervical screening programmes. 40,43,69,71–73 Uptake across screening programmes has consistently been lower in London than in the rest of the country, and this has in part been attributed to its diverse population. 73–75

Many of the studies which have sought to explain reasons for ethnic disparities in screening uptake originate from the USA and present insights relating to black American, Hispanic, Latino and other ethnic groups. Importantly, many of the structural and financial barriers exposed in US studies do not apply to the English health-care system, in which health care is free at the point of access and bowel cancer screening is made available through a nationally organised screening programme. 44,76–78 Their findings therefore offer limited scope for comparison with the UK setting.

A number of UK studies have found that reasons for low or late uptake of breast and cervical screening by minority ethnic women include low knowledge and awareness of these cancers and related screening services;75,79–81 inaccurate screening registers;82 misconceptions about the smear test; fear; embarrassment and negative previous experience;75,81 language, literacy and administrative difficulties; cultural values and beliefs; misconceptions about perceived risk; concerns about surgery hygiene; and poor attitudes of GPs. 73,74 Reasons for non-uptake of bowel cancer screening are likely to include some of those identified for breast and cervical screening programmes, but may also relate to the way in which bowel cancer screening is offered by written invitation requiring home-based self-completion of the gFOBt, with no face-to-face contact with a medical professional.

Research exploring acceptability of the gFOBt among minority ethnic communities is limited to a single study undertaken prior to the initiation of the NHS BCSP involving participants from diverse minority ethnic groups, most of whom had not yet been invited to bowel cancer screening. 42 The study found that although people supported the principle of screening and completing a gFOBt once it had been explained to them, many participants would not respond to postal invitations without prior warning being given, preferably by trusted local sources, invitees would require support from family members to translate information materials and translated materials could pose problems owing to poor literacy in their first language and limitations of translations because of dialects spoken. 42 Two studies exploring low uptake of bowel cancer screening by FS in diverse minority ethnic groups reported low knowledge and awareness of bowel cancer, anxiety about test invasiveness, fear of cancer, language difficulties, religious sensitivities and embarrassment as barriers to participation. 55,70 However, the relevance of these findings to low uptake of gFOBt is limited owing to differences in screening test procedures. Importantly, no studies have explored explanations for the differences in gFOBt uptake identified in the Muslim, Sikh and Hindu faith communities. 42 The UK South Asian community comprises multiple ethnic groups with a diversity of religious, linguistic, cultural and geographical origins, and there have been calls for greater attentiveness to this heterogeneity in health research involving participants of South Asian origin. 83,84

Aims

1. To explore reasons for the variations in bowel cancer screening uptake between South Asian Muslim, Sikh and Hindu faith groups.

2. To explore reasons for low uptake of bowel cancer screening in all South Asian communities and identify possible methods by which uptake might be improved.

Objective

To understand reasons for low uptake of gFOBt screening by UK South Asian communities using key informant interviews with participants representing Muslim, Hindu and Sikh faith groups in London.

Methods

Results

Key informants provided detailed commentaries about how their communities would be likely to respond to an invitation to take part in the NHS BCSP. Results are presented as three main themes relating to low uptake of bowel cancer screening that were described across faith groups: limitations posed by the written word, low awareness of bowel cancer and screening, and difficulties around faeces and gFOBt completion. Within each theme we also report suggestions to increase accessibility and uptake. Finally, we present reasons for low uptake specific to Muslim Bangladeshi and Sikh faith groups. Data extracts are identified by community represented and interview number (see Table 3).

Discussion

We identified common reasons that may explain ongoing low uptake of bowel cancer screening across South Asian faith groups. In all three faith communities, the delivery of bowel cancer screening using a written approach directed at the individual was considered likely to be inaccessible to a significant number of South Asian people of screening age. We also identified low awareness of the existence and purpose of bowel cancer screening and of cancer curability. In addition, there were potential difficulties with gFOBt kit completion linked to the requirement to deal with faeces and test complexity.

This study is the first, to our knowledge, to explore differences between South Asian faith groups in the reasons for low uptake of bowel cancer screening. Uptake of bowel cancer screening within England’s South Asian population is lowest in the South Asian Muslim community. 42 This may, in part, be explained by our finding that communication via written materials is particularly inappropriate for the London Bangladeshi Muslim community owing to the largely oral culture of this community. The second lowest uptake of bowel cancer screening in the South Asian population is reported among the Sikh community. 42 Our finding that reluctance to talk about cancer is linked to social stigma surrounding cancer within this community may go some way to explain the poorer uptake in this faith group.

Our findings that written invitation materials may pose particular challenges and that, even when translated, written invitation materials are of limited value owing to widespread low literacy specifically among older members of South Asian communities (to whom bowel cancer screening is offered) are in common with previous research. 42 Difficulties related to language have also been found in relation to low uptake of other screening programmes. 73–75

Although previous studies have identified reluctance to talk about cancer linked with fearful perceptions of cancer in mixed South Asian minority ethnic groups, these studies have not attempted to distinguish between faith groups regarding the specific experience and impact of social stigma surrounding cancer. 42,81

Our finding of low awareness of the purpose and value of bowel cancer screening across South Asian faith communities confirms previous findings. 42,55,73,75,81 A number of studies also found low knowledge and awareness of cancer and fearful perceptions of cancer in minority ethnic groups,42,55,70,73,75,80,81 which mirrors our finding that awareness of cancer curability was perceived to be low across South Asian faith communities. Finally, we found perceived difficulties associated with the sampling and storage of faeces in order to complete the gFOBt kit, including limitations on getting help from family members owing to the personal nature of the test, which were also experienced within the majority (white European and African Caribbean) population. 32,50,51

We identified agreement across faith communities in the preferred approaches to increase accessibility and awareness of bowel cancer screening offered by the NHS BCSP. In common with previous studies, we have identified an overwhelming preference for face-to-face, verbal and interactive approaches in order to provide information and raise awareness about the availability and purpose of bowel cancer screening. 42,74 We also identified a desire for the provision of information to take place ‘in language’ within community, faith and/or social settings;42,55,73 and the potential value of ethnic community media to publicise the NHS BCSP and gFOBt completion. 42,55 A simplified test kit and the option to seek screening guidance from the GP or practice nurse were noted as further potential strategies to increase uptake. Our findings reiterate existing evidence regarding strategies to improve accessibility and uptake of health services more generally for South Asian communities, but we have also demonstrated that specific South Asian ethnocultural groups may have distinctive features and needs.

Conclusion

Our findings identify barriers to bowel cancer screening uptake in the UK for many people within South Asian communities that persist despite being first identified over a decade ago. 42 Design and evaluation of interventions to increase accessibility and awareness of bowel cancer screening are required and should incorporate verbal and interactive approaches in the appropriate language for the target community in order to address the limitations of written correspondence. An encouraging recent intervention study tested the provision of health promotion information either face to face or by telephone through general practices with a large minority ethnic population and found that these approaches led to significant improvements in the likelihood of bowel cancer screening uptake. 88 Approaches should further be delivered within community and faith settings in partnership with representatives from these settings, and be backed up with the use of local ethnic media. Given the role of children in mediating access to health for older people across South Asian communities, it may also be beneficial to raise general and practical awareness of the NHS BCSP across all age groups. Interventions involving GPs opportunistically offering screening to low uptake groups could be explored. Design and delivery of interventions may need to be further tailored to the distinct needs of specific South Asian minority ethnic and faith groups, for example, by devising ways to tackle the social stigma associated with cancer in the Sikh community.

Reasons for low uptake of bowel cancer screening are predominantly shared across South Asian faith communities. However, specific cultural issues such as non-written culture or social stigma surrounding cancer may further explain low uptake in individual faith groups. Strategies to increase access to screening should move away from the use of written messages mailed directly to individuals. Locally targeted efforts using verbal and face-to-face approaches delivered in community settings, and backed up with the use of local ethnic media, should be developed to enable people from South Asian communities to make an informed choice about what screening can offer.

Introduction

The first ASCEND intervention to be evaluated nationally in workstream 3 involved the inclusion of a ‘gist’ leaflet with the invitation letter and materials sent out by the NHS BCSP. In this chapter, we will first describe the theoretical background to this intervention and we will then report how we carried out a think-aloud study, which describes how the current NHS BCSP materials are received and how we then developed the leaflet and tested it for comprehension with people with low levels of literacy. Finally, we provide details of a pilot study that tested if the leaflet would influence people’s intention to take part in screening. The results of the national RCT of the ‘gist’ intervention are reported in Chapter 10.

Theoretical background

Fuzzy trace theory (FTT) is a theory of judgement and decision-making. 89,90 It has recently been applied to the field of medicine and health91 and is a dual-processing theory which proposes that information is encoded into memory in two parallel forms: a gist representation and a verbatim representation. Gist representations are defined as vague, qualitative concepts capturing the bottom-line meaning of information. As such, they are subjective to the individual and affected by a range of different core values. In turn, these core values are influenced by factors such as emotional state, general world view, literacy and numerical ability. In contrast, verbatim representations are precise and quantitative and said to capture the surface form of the information (i.e. they are literal). For example, an individual reading ‘The Facts’ booklet would first read about the efficacy of gFOBt screening in reducing bowel cancer deaths. A verbatim representation of this would be ‘gFOBt screening reduces my chances of dying from bowel cancer by 16%’ and a gist representation might be ‘my chances of dying would be lower if I take part in gFOBt screening’.

Gist representations are formed along a continuum, which ranges from the simplest to most complicated. People exhibit a consistent preference to use the simplest form of gist available when making a judgement or decision89,92 particularly at older ages. 93 For example, in a sample of students and physicians making judgements on the cardiac risk of nine hypothetical patients, better discriminatory decisions resulted from processing information in an ‘all-or-none’ fashion, as opposed to weighing up several details at once. 94

Fuzzy trace theory argues that by presenting information in a format more closely aligned with preferred processing styles (i.e. gist), retrieval will be improved and the cognitive burden placed on the reader will be reduced. 95 This will be particularly true for people with lower levels of health literacy and numeracy. 96–98

It has therefore been suggested that pre-formulated gist-based information may improve gist extraction, reduce cognitive burden and improve public understanding of screening. 95 As such, FTT provides an elegant theoretical model on which to base a cancer communication intervention that aims to reduce socioeconomic inequalities in screening.

Study A: a ‘think-aloud’ study

A version of the ‘think-aloud’ study has been published in Smith et al. 99 This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

In order to inform the design and content of our ‘gist’ leaflet, we carried out a ‘think-aloud’ study to provide detailed commentary on how individuals process the information contained within the NHS BCSP ‘The Facts’ booklet. We set out to identify areas of the existing booklet (‘The Facts’) that were difficult to read, confusing to the reader or detrimental to motivation in order to quantify them within a typology of utterances. Furthermore, we sought to identify additional responses to the information using a more in-depth qualitative analysis.

Methods

Results

Content analysis

In the 18 interviews, 270 reading mistakes were recorded (mean 15 per person; range 0–59). The interviews yielded 776 coded utterances (mean 43.1 per person; range 8–95), which were analysed within the predetermined framework.

There was substantial variation in the types of comments made by participants (Figure 4). The comprehension theme was largely made up of comments that implied higher-level understanding (i.e. deep processing, 17.9% of all comments) or repetitions of the text and unsubstantiated self-reported knowledge (i.e. surface processing, 15.2%).

FIGURE 4.

Typology of participant utterances. Reproduced from Smith et al. 99 This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Responders were significantly more likely than non-respondents to be female [χ²(1) = 16.09; p < 0.001], older [t(4401) = 6.16; p < 0.001], from an affluent neighbourhood [χ²(1) = 115.07; p < 0.001] and be in a home with two or more invitees [χ²(1) = 4.05; p = 0.044].

Miscomprehension was less common (6.2%); however, this still amounted to 48 instances of mistakes or self-reported lack of understanding. There were a high number of comments in the emotional theme. Emotionally negative statements were three times more common than emotionally positive statements (18.0% and 5.7%, respectively). The information preferences theme suggested that people desired further information on specific aspects of the booklet (unanswered questions: 15.2%), while others suggested improvements to the style and layout of the booklet (layout: 13.1%). A minority of statements questioned the necessity of certain information that they had just read (unnecessary information: 4.8%) and utterances rarely alluded to whether the participant felt motivated (1.4%) or demotivated (2.5%) by information in the booklet.

Designing the ‘gist’ leaflet

The Department of Health policy for screening communications endorsed in the UK cancer strategy is to ‘empower the greatest number possible . . . to make an informed choice to participate in cancer screening’ (© Crown copyright 2010; contains public sector information licensed under the Open Government Licence v3.0). 111 We therefore needed to ensure that the gist leaflet would be accommodated within this policy context. 112 The NHS BCSP specified that our leaflet must be provided in addition to, rather than instead of, the existing booklet. Although this is not the ideal situation according to FTT, it represents a compromise for using psychological theory within the constraints of an organised health-care system.

Study B: user testing the ‘gist’ leaflet

A version of the user testing study has been published in Smith et al. 143 © 2013 The Authors. Published by Elsevier Ireland Ltd. Open access under CC BY license.

Study C: a pilot study to evaluate the ‘gist’ leaflet

A version of the gist evaluation RCT has been published in Smith et al. 151 Parts of this text have been reproduced from Smith SG, Kobayashi LC, Wolf MS, Raine R, Wardle J, von Wagner C. The associations between objective numeracy and colorectal cancer screening knowledge, attitudes and defensive processing in a deprived community sample. J Health Psychol 2016;21:1665–75,151 with permission from Sage.

We used a RCT design to compare sociocognitive outcomes with the ‘gist’ leaflet as a supplement to standard information (gist + facts) and standard information alone (facts). Interactions with levels of numeracy were also examined. In keeping with FTT, we hypothesised that the ‘gist’ leaflet would increase knowledge and screening intentions and that the difference between conditions would be stronger among low-numeracy individuals.

Results

The study ran between July 2012 and March 2013, with questionnaires returned up to May 2013 (Figure 5). Individuals (n = 4452) were randomised by household (n = 3706), with 2216 allocated to the ‘facts’ group and 2236 to the ‘gist + facts’ group (Table 7). A total of 3631 (81.6%) individuals were sent a reminder [the ‘facts-only’ group = 1808 (81.6%); the ‘gist + facts’ group = 1823 (81.5%)] approximately 3 weeks after the initial invitation (median 22 days, range 22–41 days).

FIGURE 5.

Numbers of participants in control ‘facts-only’ and intervention ‘gist + facts’ groups.

TABLE 7 - Characteristics of randomised individuals using GP records (n = 4452)

Characteristics	All (%), n = 4452	‘Facts-only’ group (%), n = 2216	‘Gist + facts’ group (%), n = 2236
Gender
Male	2420 (54.4)	1194 (53.9)	1226 (54.8)
Female	2032 (45.6)	1022 (46.1)	1010 (45.2)
Number in household
1	2984 (67)	1476 (66.6)	1508 (67.4)
2	1400 (31.4)	714 (32.2)	686 (30.7)
3	60 (1.3)	22 (1.0)	38 (1.7)
4	8 (0.2)	4 (0.2)	4 (0.2)
IMD score quintiles
1 (low deprivation)	996 (22.4)	473 (21.4)	523 (23.5)
2	794 (17.9)	412 (18.7)	382 (17.1)
3	930 (21.0)	462 (20.9)	468 (21.0)
4	834 (18.8)	420 (19.0)	414 (18.6)
5 (high deprivation)	884 (19.9)	441 (20.0)	443 (19.9)
Age	51.1 (4.1)	51.2 (4.1)	51 (4.2)

Respondents were excluded from analysis if questionnaire data on age and gender did not match GP records (n = 26) or if the study materials were not delivered as intended (n = 23). Exclusions were approximately equal for both study groups. A sample of 4403 individuals remained and this figure was used as the denominator for calculating a response rate. A total of 1269 questionnaires were returned, of which 964 were completed and provided outcome data, giving a response rate of 21.9%. The response rate varied between the practices (Manchester, 13.0%; Liverpool a, 18.1%; Liverpool b, 19.6%; Stockport, 31.8%) and these differences were statistically significant [χ²(3) = 128.76; p < 0.001].

Questionnaire data indicated that a high proportion of participants were married (66.9%), white (83.8%) and in employment (72.2%) and had either some formal education (49.9%) or a degree-level education (36.5%) (Table 8). The sample was well distributed by gender (51.4% female) and age group (45–49 years, 32.7%; 50–54 years, 34%; 55–59 years, 33.3%). Despite the educated sample, a high proportion answered the numeracy item incorrectly (35.3%) or did not provide an answer (10.5%).

TABLE 8 - Participant characteristics for respondents using questionnaire data

The total number may not round to 964 owing to missing data.

Characteristics	n (valid %)
Gender
Male	466 (48.6)
Female	493 (51.4)
Age (years)
45–49	313 (32.7)
50–54	325 (34.0)
55–59	319 (33.3)
Marital status
Married	640 (66.9)
Unmarried	317 (33.1)
Ethnicity
White	799 (83.8)
Black	42 (4.4)
South Asian	58 (6.1)
Other	55 (5.8)
Education
No formal education	128 (13.6)
Some formal education	471 (49.9)
Undergraduate or higher	345 (36.5)
Employment status
Employed	689 (72.2)
Unemployed	95 (10.0)
Full-time homemaker	44 (4.6)
Retired	37 (3.9)
Student	5 (0.5)
Disabled	84 (8.8)
Numeracy
Correct	523 (54.3)
Incorrect	340 (35.3)
Missing	101 (10.5)

Respondents had a high level of knowledge (mean 7.70, SD 1.74 out of a possible 9) and a large proportion (93.1%) were classified as having ‘adequate’ gist knowledge. Individuals in the ‘gist + facts’ group were more likely to have adequate knowledge (95.2%) than those in the ‘facts-only’ group [90.9%; χ²(1) = 6.74; p = 0.009] (Table 9). Low-numeracy individuals were less likely to have adequate knowledge [89.0% vs. 96.6% (7.6% difference) χ²(1) = 21.34; p < 0.001], but there was no significant group by numeracy level interaction [odds ratio (OR) = 0.42; p = 0.130].

TABLE 9 - Differences between study groups on outcome measures

Variable	‘Gist + facts’ group (%)	‘Facts-only’ group (%)	Significance
Intention	75.7	73.8	χ2(1) = 0.45; p = 0.50
Gist knowledge	95.2	90.9	χ2(1) = 6.74; p = 0.009

A large proportion of the sample said they would ‘definitely’ (74.7%) or ‘probably’ (22.9%) participate in screening and very few reported that they would ‘probably not’ (1.6%) or ‘definitely not’ (0.8%) participate. There were no significant differences between the two groups in the proportion of individuals who definitely intended to participate [χ²(1) = 0.45, p = 0.50] (see Table 9). Low-numeracy individuals were less likely to say they would ‘definitely’ participate in bowel cancer screening [71.2% vs. 77.7% (6.5%); χ²(1) = 5.40; p = 0.020], but there was no significant group by numeracy level interaction (OR = 1.02; p =0 .936).

In the whole sample, 81.7% reported reading all of the information at least once, but those with poor numeracy were less likely to have read them [74.4% vs. 88.0% (13.6% difference); χ²(1) = 29.56; p < 0.001]. There was no significant group by numeracy level interaction in terms of reading the information (OR = 1.37; p = 0.367).

The ‘gist + facts’ group were marginally less likely to have read the materials than the ‘facts-only’ group [79.7% vs. 83.9%; χ²(1) = 2.83; p = 0.093]. Within the ‘gist + facts’ group, participants were more likely to read at least some of the ‘gist’ leaflet (88.6%) than ‘The Facts’ booklet (80.5%). Figure 6 shows that participants in the ‘gist + facts’ group with low numeracy were slightly less likely to read the ‘gist’ leaflet [84.5% vs. 92.5% (8.0% difference); χ²(1) = 7.86; p = 0.005] and even less likely to read ‘The Facts’ booklet [72.2% vs. 88.5% (16.3% difference); χ²(1) = 21.07; p < 0.001]. There was also a significant difference in reading between the low- and high-numeracy groups in the ‘facts-only’ group [79.1% vs. 88.1% (9.0% difference); χ² = 8.56; p = 0.003] (see Figure 6).

FIGURE 6.

Proportion of participants who reported reading at least some of their allocated materials by numeracy group. F only, facts only; G + F, gist + facts.

Patient and public involvement and engagement

At each stage of the leaflet development, we sought input from members of the public as well as from individuals specifically identified to have low health literacy.

The charities ContinYou (then specialising in working with adults with low literacy nationally) and SAfH (a London-based organisation working alongside marginalised local people and their communities in order to improve health and well-being) assisted the research team in recruiting individuals with low literacy for the development of the gist-based information leaflet.

Primary Care Research Networks in Manchester and Liverpool assisted the research team in identifying GPs situated in areas of high deprivation in order for us to undertake a RCT via a postal questionnaire survey regarding intention to participate in bowel cancer screening.

We described the development of the gist leaflet and the results of the primary care-based pilot study were presented to an advisory meeting comprising the study team, representatives from third-sector organisations and patient representatives. At the meeting, copies of the gist leaflet were also provided and additional input was given before the final version was tested in the RCT.

Summaries of the findings of the trial carried out through GPs were sent to participants who ticked a box requesting that details were sent to them.

Conclusion

Following a consideration of acceptability of current NHS BCSP information materials, our research team designed and user tested a simple gist-based leaflet, which aimed to provide information to help people make an informed decision on whether or not to accept an offer of bowel cancer screening. This gist leaflet was tested in a national RCT (intervention 1, workstream 3) in November 2012 and the results are reported in Chapter 10.

Introduction

The second ASCEND intervention to be evaluated nationally in workstream 3 involved the inclusion of a ‘narrative’ leaflet with the invitation letter and materials sent out by the NHS BCSP. Support for this intervention was obtained from the results of the focus group study described in Chapter 3. In particular, the theme ‘the power of talk’, which described how learning of other people’s experience with bowel cancer and bowel cancer screening helped normalise the screening process and ‘tip’ people into making a personal decision to take part in screening. In the focus groups, this mostly referred to experience of family and friends; however, as this was not possible in the format of a national leaflet, we attempted to simulate this effect by using the stories of other people who had undergone CRC screening. Specifically, we tried to appeal to a broad representation of people from the target age range by using a mixture of males and females as well as individuals from ethnic minority backgrounds. In addition, focus group findings concerning resistance to handling faecal matter and the implications of knowing gFOBt results were also highly pertinent.

In this chapter, we will first describe the theoretical background to this intervention. Second, we will describe how we collected the narratives for use in the leaflet and how we then developed and tested the leaflet with several different groups, including experts and lay people. Third, we provide details of a pilot study which tested if the leaflet could influence people’s beliefs about bowel cancer screening and intention to take part in screening. The results of the national RCT of the ‘narrative’ intervention are reported in Chapter 10.

Background

Cancer screening information is usually presented didactically (i.e. factual, statistical information)155 and the information material currently delivered to individuals eligible for bowel cancer screening is no exception. However, narrative based communication (i.e. stories with character and event examples) is suggested as a format more attuned to engaging various audiences. 156 Narratives are thought to reduce counter-arguing, facilitate mental imagery and provide role models of behaviour, making them particularly useful for enhancing health behaviours. 156–158

The positive influence of narratives has been highlighted within a number of health-related behaviours, including breast cancer screening, skin cancer prevention and hepatitis B vaccinations. 159–161 Intentions to take part in such health-promoting activities have been found to be higher after exposure to narrative information compared with either statistical information or no information at all. In a US-based study by Dillard et al. ,162 incorporating narratives into information about bowel cancer screening increased perceived personal risk of bowel cancer. This was a positive result in accordance with theoretical models of behaviour change such as the Extended Parallel Processing Model163 and the Health Belief Model,164 which assert that people need to consider themselves susceptible to a disease in order to ‘motivate’ preventative behaviours. In addition, the inclusion of the narrative had the additional positive effect of reducing the impact of perceived barriers which, in combination with perceived susceptibility, lead to positive behaviour change. Consequently, narratives were found to significantly increase interest in receiving a colonoscopy. 162 A more recent US study165 reported that individuals presented with a bowel cancer screening information leaflet containing a narrative were four times more likely to participate in bowel cancer screening than those given information without a narrative. The impact of narrative information with regard to beliefs about bowel cancer screening, intention to do the gFOBt and actual screening behaviour has not previously been investigated in the UK.

Accessing narrative health information is becoming easier owing to the array of online resources that are now available. Healthtalkonline166 and Cancer Genetic Storybank167 are examples of websites dedicated to using personal experiences to educate the viewer about selected health issues. However, the population we are targeting with the gFOBt may have limited use of the internet. In a recent Ofcom report on media literacy, ‘narrow’ users (i.e. use of the internet is limited) were more likely to be aged ≥ 55 years and in lower SEC groups. 168 Therefore, despite limitations of design (e.g. length and number of stories presented), the written paper form remains an important medium, particularly to the age group served by the NHS BCSP, and fits within the format of the current system.

Aims

1. To collect personal narratives from individuals who have experience of taking part in the NHS BCSP.

2. To develop a narrative leaflet, to supplement current information materials sent out by the NHS BCSP.

3. To test if the narrative leaflet had an impact on beliefs about screening, including intention to be screened, among individuals of pre-screening age.

Collecting personal ‘narratives’ of screening

For the content of the narrative leaflet, individuals (n = 20) who had previously taken part in the NHS BCSP were interviewed about their personal screening experience. Efforts were taken to ensure a mix of screening outcomes. The interviews were transcribed and then each transcript reviewed with suitable extracts highlighted for possible inclusion in the leaflet. The content of the leaflet was decided within the ASCEND research group. A draft of the leaflet was presented to the Social Marketing Team at Stirling University, Stirling, UK, and then evaluated via interviews and focus groups with pre-screening-aged men and women, and further refinements were subsequently made. Finally, we evaluated the leaflet using the Suitability and Comprehensibility Assessment of Materials questionnaire. 169 These stages of development are described in more detail below.

Designing the narrative leaflet

We developed the narrative leaflet according to the principles set out by the Department of Health’s Improving Outcomes: A Strategy for Cancer111 described in Chapter 5. As was the case for the first ASCEND intervention, the ‘gist’ leaflet, the ‘narrative’ leaflet was provided in addition to, rather than instead of, the existing booklet. This was to ensure that every individual continued to have access to information necessary for making an informed choice about bowel cancer screening participation. 112

Our aim was to ensure that the narrative leaflet presented a variety of credible messengers with whom our target population could identify, but without being overwhelmed by the amount of material provided. The leaflet went through many iterations during the design process. Below, we summarise four iterations of the leaflet that represent the main design changes, along with summaries of specific input for each design and present the final leaflet used in the intervention.

A pilot study to evaluate the ‘narrative’ leaflet

A version of this study has been published in McGregor et al. 171 © 2015 McGregor et al. ; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

A RCT was conducted to test the hypothesis that the inclusion of a narrative information leaflet would lead to a positive shift in beliefs about bowel cancer screening, beliefs that have previously been found to be predictive of health intention and behaviour.

The Extended Parallel Process Model163 predicts that positive behaviour change in response to a health threat (i.e. cancer) will occur if there is a high level of perceived susceptibility to the disease, in addition to a strong belief that the proposed behaviour can be successfully carried out and will successfully reduce the threat. The narrative leaflet was designed with this in mind and, therefore, the presentation of various people who had already successfully completed the test as well as selected quotations that illustrated surprise at a diagnosis and relief at having cancer found and treated early were anticipated to increase self-efficacy for test completion, perceived personal risk of getting bowel cancer and perceived response efficacy of the test.

The Health Belief Model164 also suggests that, for a behaviour to be elicited, perceived barriers to the behaviour should be low and the perceived benefits high. We included specific quotations in the narrative leaflet to counter-argue known test barriers (i.e. disgust with test procedure and the belief that screening is only for those with symptoms),172,173 hypothesising that endorsement of such barriers would decrease and quotations portraying reassurance following participation would help enhance the perceived benefit of peace of mind from doing the test. 174

Results

A total of 1256 people (SI = 606, SI + narrative = 650) returned a completed questionnaire (30.5% response). Those who provided age information inconsistent with general practice records (n = 35) were removed from the analysis. Therefore, the final sample consisted of questionnaire data from 1221 participants (SI, n = 590; SI + narrative, n = 631). The two groups were similar in terms of sociodemographic characteristics (Table 12). Of those who answered the introductory question(s), the majority self-reported that they had read at least some of the information materials provided (SI, 96%; SI + N, 94%; ‘The Facts’ booklet and narrative leaflet, 90%).

TABLE 12 - Pilot study participant characteristics

Characteristic	SI, N = 590	SI + N, N = 631
Age (years)
Mean (SD)	51.94 (4.31)	51.80 (4.16)
Missing	–	–
Gender, n (%)
Female	334 (56.6)	353 (55.9)
Male	256 (43.4)	278 (44.1)
Missing	–	–
Ethnicity, n (%)
White	513 (86.9)	547 (86.7)
Non-white	75 (12.8)	82 (13.0)
Missing	2 (0.3)	2 (0.3)
Socioeconomic deprivation score, n (%)
0 (least deprived)	326 (55.3)	362 (57.4)
1	145 (24.6)	147 (23.3)
2	71 (12.0)	77 (12.2)
3 (most deprived)	19 (3.2)	16 (2.5)
Missing	29 (4.9)	29 (4.6)

t-tests

The results of the t-tests are presented in Tables 13–15. The group that received the additional narrative leaflet perceived themselves to be at higher risk of bowel cancer if they did not participate in bowel cancer screening (p = 0.045) and were more likely to believe that doing the screening test would reduce their chances of dying from bowel cancer (p = 0.008) (see Tables 13 and 15, respectively). In addition, the group with the narrative leaflet were less likely to perceive doing the test as disgusting (p = 0.007) and more likely to believe that doing the test would provide them with peace of mind (p = 0.002) (see Table 15).

TABLE 13 - Between-group comparison of responses to question on perceived risk

Belief	Group	n	Response (%)					Results
			Strongly disagree	Disagree	Not sure	Agree	Strongly agree	Mean (SD)	t-test
Perceived risk	SI	583	4.3	23.2	35.7	29.2	7.7	3.13 (0.99)	t(1208) = –2.00; p = 0.045
	SI + N	628	5.3	20.3	30.0	33.5	11.0	3.25 (1.06)

TABLE 14 - Between-group comparison of responses to questions on beliefs about CRC screening

Belief	Group	n	Response (%)				Results
			Strongly disagree	Disagree	Agree	Strongly agree	Mean (SD)	t-test
Self-efficacy	SI	584	0.7	2.9	62.7	33.7	3.29 (0.55)	t(1208) = –1.92; p = 0.055
	SI + N	628	0.8	2.4	57.2	39.6	3.36 (0.57)
Response efficacy	SI	582	2.2	8.1	60.0	29.7	3.17 (0.66)	t(1201) = –2.64; p = 0.008
	SI + N	627	2.1	5.9	54.7	37.3	3.27 (0.66)
Anticipated disgust	SI	584	28.9	52.2	15.9	2.9	1.92 (0.75)	t(1204) = 2.69; p = 0.007
	SI + N	622	34.1	52.3	11.7	1.9	1.81 (0.71)
Symptom absence	SI	577	44.0	49.0	4.2	2.8	1.67 (0.70)	t(1196) = 1.39; p = 0.165
	SI + N	621	49.9	43.2	3.9	3.1	1.60 (0.71)
Peace of mind	SI	582	1.0	6.7	61.0	31.3	3.22 (0.61)	t(1199) = –3.15; p = 0.002
	SI + N	626	1.0	4.5	54.6	39.9	3.33 (0.61)

TABLE 15 - Between group comparison of responses to question on intention

Belief	Group	n	Response (%)				Results
			Definitely not	Probably not	Yes, probably	Yes, definitely	Mean (SD)	t-test
Intention	SI	582	0.3	3.6	27.5	68.6	3.64 (0.57)	t(1208) = –1.99; p = 0.048
	SI + N	628	1.6	1.8	24.0	73.6	3.71 (0.53)

The group who received the additional narrative leaflet also showed a significantly stronger intention to take part in screening in the future [mean (SD) = 3.71 (0.53) vs. 3.64 (0.57); t(1208) = –1.98; p = 0.048]. Indeed, the proportion of participants who indicated that they ‘definitely’ intended to take part in screening in the future was 5% higher in the group who received the additional narrative leaflet (74% vs. 69%) (see Table 13).

Both groups generally agreed that they were confident to complete the gFOBt kit and correctly disagreed that the test was only for those who had symptoms; however, there was no statistically significant between-group difference on the strength of either belief (p > 0.05).

Mediation analysis

A mediation analysis was conducted to help explain how the narrative affected intentions by modifying specific beliefs about screening. The direct effect of intervention on each belief, including intention, and of each belief on intention was confirmed with multiple regression. The parallel multiple mediator model is presented in Table 10. The model was based on a sample of 1106 people (SI, n = 529; SI + N, n = 577) and accounted for 29.8% of the variance in intention.

Age, gender, ethnicity and socioeconomic deprivation were included as control variables in the model. Older age was associated with stronger intention [β = 0.008, t(1095) = 2.55; p = 0.014], women were more likely to intend to do the bowel cancer screening test than men [β = 0.066, t(1095) = 2.34; p = 0.019] and a higher socioeconomic deprivation level (i.e. more deprived) was associated with lower intention [β = –0.061, t(1095) = –3.43; p < 0.001]. There was no association between ethnicity and intention (p = 0.135). The relationship between group and beliefs, beliefs and intention, and group and intention were retained when controlling for gender, age, deprivation and ethnicity. The direct effects are presented in Figure 7 and Table 16.

FIGURE 7.

Parallel multiple mediator model showing relationships between group, intention and beliefs. Unstandardised beta coefficients show direct effects. R² = 0.2978, n = 1106. a, p < 0.05; b, p < 0.001; c, p < 0.01. Reproduced from McGregor et al. 171 © 2015 McGregor et al. ; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

TABLE 16 - Regression coefficients, standard errors and model summary information for the parallel multiple mediator model depicted in Figure 7

Unstandardised coefficient.

Degrees of freedom = 1095.

Holding all other beliefs and group constant.

Holding beliefs about screening constant.

Reproduced from McGregor et al. 171 © 2015 McGregor et al. ; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Variable	βa	SE	t b	p-value
Direct effect of group on each belief
Perceived vulnerability	0.135	0.062	20.19	0.029
Self-efficacy	0.047	0.033	10.44	0.150
Response efficacy	0.095	0.040	20.38	0.017
Anticipated disgust	–0.093	0.044	–20.13	0.034
Symptom absence	–0.047	0.041	–10.14	0.254
Peace of mind	0.107	0.036	20.97	0.003
Direct effect of each belief on intentionc
Perceived vulnerability	0.058	0.014	40.04	0.000
Self-efficacy	0.215	0.030	70.24	0.000
Response efficacy	0.051	0.024	20.13	0.033
Anticipated disgust	–0.060	0.021	–20.93	0.004
Symptom absence	–0.127	0.022	–50.67	0.000
Peace of mind	0.154	0.028	50.44	0.000
Total effect of group on intention
Group	0.067	0.032	20.08	0.038
Direct effect of group on intentiond
Group	0.016	0.028	0.578	0.564

Importantly, the direct effect of group on intention reduced and became non-significant when the belief variables were controlled for, indicating that the leaflet affected intention through beliefs (see Figure 7 and Table 16).

Indirect effects were assessed using bias-corrected bootstrap CIs. Perceived peace of mind, vulnerability to bowel cancer, anticipated disgust and perceived test efficacy all mediated the effect of group on intention. The SI + N group had stronger intentions to be screened as a result of their tendency to, in order of strength of influence, (1) more strongly believe that screening will provide peace of mind (β = 0.0167, 95% CI 0.0061 to 0.0319), (2) perceive themselves as more vulnerable to bowel cancer if they do not have screening (β = 0.008, 95% CI 0.0014 to 0.0181), (3) consider the screening test as less disgusting (β = 0.006, 95% CI 0.0007 to 0.0143) and (4) more strongly believe that screening would reduce their chances of dying from bowel cancer (β = 0.005, 95% CI 0.0004 to 0.0136) than the SI group. Examining the CIs for each mediator contrast showed that the indirect effect of peace of mind was significantly stronger than the indirect effect of response efficacy (β = –0.012, 95% CI –0.0275 to –0.0009). No other significant contrasts were found, suggesting that each of the other mediator indirect effects were of comparable strength.

Discussion

The addition of a narrative leaflet to standard information material had a positive effect on a number of beliefs about bowel cancer screening, which, in turn, significantly increased respondents’ intention to participate in the screening programme.

The mediation analysis found that the narrative leaflet influenced intention to be screened predominantly through its ability to strengthen the benefit of anticipated peace of mind from screening, enhance feelings of vulnerability to bowel cancer without screening, reduce perceived disgust with the procedure, and enhance the belief that screening could reduce your chance of dying from bowel cancer.

Although intention to be screened may not directly lead to screening behaviour (the ‘intention–behaviour gap’), it remains an important prerequisite. Previous research has found that lower perceived barriers and higher perceived benefits of screening are predictive of both intention to be screened and screening behaviour itself180 and, therefore, the narrative leaflet’s ability to positively manipulate factors addressing a selection of benefits and barriers suggest potential for an influence on screening behaviour.

A limitation of this study is the percentage of people who returned completed questionnaires (30.4%). This may have subsequently added bias to the results. Within the SI group, a high percentage of respondents (96%) said they would ‘probably’ or ‘definitely’ do the gFOBt and the variation of socioeconomic deprivation was limited within groups; therefore, it could be suggested that the study failed to recruit the very people we hoped the narrative leaflet would influence. Indeed, the socioeconomic deprivation measure used may have overestimated the number of people in London within the more deprived groups; the selected measure was itself a limitation because London is not a fair domestic representation of the UK, with car and home ownership rates lower than in the rest of England due to circumstances not necessarily linked to deprivation. 181,182

A reason for the low participation rate may have been the subject matter. The leaflet was designed to help reduce barriers to screening but the initial invitation cover letter introducing the topic of bowels (a topic of conversation often regarded as socially unacceptable)183 may have put people off participating any further, with the result that the mock NHS invitation envelope may not have been opened and the leaflet not seen. Following on from this is the response burden associated with participation [i.e. reading a 16-page booklet (‘The Facts’) and then completing and returning a questionnaire]. The multiple tasks involved may have deterred participation, not only with respect to the length of time needed to participate but also the additional onus on reading material. Although the leaflet fitted the format of the NHS BCSP, additional reading material may not be an effective way of engaging people, especially those with low literacy levels.

The salience of the topic being investigated is also considered an important determinant of response rates. 184 Bowel cancer screening is currently offered to people aged 60–74 years as part of the NHS BCSP, yet we purposively wanted to obtain the views of those naive to screening and, therefore, invited people aged 45–59.5 years. As a result, it may be that the relevance of the topic to the invited individual was low and, therefore, participation was not considered a priority.

Despite the limitation of a low response rate, this study has shown that the use of a paper-based narrative leaflet, tailored only to the broad characteristics of the eligible population (i.e. men and women aged > 60 years), has the potential to positively impact beliefs about bowel cancer screening and intention to be screened.

Within a real-world situation, the NHS envelope containing the screening invitation and information material will be delivered directly, with no additional research tasks requested, and to people within the eligible age bracket. Consequently, more people are likely to engage with the narrative leaflet when it is sent as part of the bowel screening programme and, therefore, it has the potential to heighten intention to be screened at a more pertinent point in the decision-making process. As the leaflet was found to enhance selected benefits and reduce selected barriers to screening, factors previously found to be predictive not only of intention but also behaviour,180 a positive impact on screening uptake looks promising. Further research in workstream 3 will assess the impact of the leaflet on actual behaviour.

Patient and public involvement and engagement

We were assisted by a number of different organisations in recruiting research participants to take part in the narrative interviews. Some were identified following their response to a request advertised by Beating Bowel Cancer, the UK’s leading charity working to promote awareness of bowel cancer. AgeUK invited us to attend a local forum to promote the study but interested members were not found to be eligible for participation. In addition, one participant was recruited when the researchers attended a health promotion event at a local library. Verbal promotion of recruitment for the narrative interviews was also conducted by the research team whenever opportunities arose within the public domain (e.g. when recruiting for workstream 1).

A local carers centre recruited members of the public to take part in two focus groups in order to provide feedback on the content and style of the narrative leaflet that was produced using the narrative interviews. An additional three telephone interviews were undertaken with individuals recruited through ContinYou (a charity working with adults with low literacy) and Groundwork (an organisation working in the most disadvantaged areas of the UK, helping to create better environments to improve people’s prospects and to promote environmentally responsible ways of living and working). The final draft of the leaflet was then reviewed by those who had taken part in the original narrative interviews (including our patient representative coapplicant).

The research team worked with primary care research networks in Cumbria and London in order to identify general practices willing to assist with recruitment of participants to take part in a small RCT concerned with assessing levels of intention to take part in bowel cancer screening.

We presented a summary of the development of the leaflet and the results of the primary care-based pilot study to an advisory meeting consisting of the study team, representatives from third-sector organisations and patient representatives. At the meeting, copies of the leaflet were also provided and additional input was given, which informed the final version used in the RCT.

A summary of the pilot study results has been sent to those who completed a questionnaire and added their contact details for the stated purpose of receiving a copy of the results. A similar summary has also been sent to those who provided the narratives for the developed leaflet.

Summary

We interviewed a variety of individuals (n = 20) with real experiences of taking part in the NHS BCSP and used these rich accounts to design a ‘narrative’ leaflet. We revised and refined the leaflet following feedback from a number of expert groups and focus groups with the general public and then evaluated its impact on beliefs about screening in a small RCT with individuals of pre-screening age (Figure 8). Following the positive results from this small RCT on screening intention, the leaflet was then tested in a national RCT (intervention 2, workstream 3) in March 2013 and the results are reported in Chapter 10.

FIGURE 8.

Flow chart showing development of narrative leaflet. SAM + CAM, suitability assessment of materials and comprehensibility assessment of materials.

Background

The results of workstream 1 highlighted the perceived detachment of the NHS BCSP from familiar health-care settings and professionals; however, it has been demonstrated that a screening invitation from a credible and trusted source, such as a GP, is more likely to be accepted185,186 and may have a specific role in addressing low uptake in disadvantaged populations. 187 Including the GP’s signature on the screening invitation has been found to increase gFOBt uptake, but such active participation is costly and time-consuming. 188 A large Australian RCT (n = 2400) with 95% power to detect a difference in participation rates found that a screening invitation naming the relevant general practice was almost as effective at increasing uptake as having the letter signed by the GP. 36 In a study by Cole et al. ,36 letters with GPE achieved a 6% higher participation rate than the regular screening invitation, although the trial lacked the power to detect socioeconomic differences across groups. There is evidence to suggest that endorsement by a GP might reduce the socioeconomic gradient in screening uptake. One study explored predictors of participation via different methods of invitation for bowel cancer screening and reported that, when deciding whether or not to take part in screening, participants with lower education relied more on their GP’s advice than written information accompanying a mailed screening invitation. 189 This suggests that a letter including endorsement by a GP could potentially encourage participation in this population.

The NHS BCSP operates independently from general practices and, although GPs are notified about their patients’ screening results or if their patients have not taken up the offer of screening, there is no additional GP involvement. Reports from the NHS BCSP pilot studies, which included telephone interviews and a focus group with individuals who had not responded to the invitation to be screened, indicate that the perceived anonymity of the NHS BCSP pre-invitation and the lack of involvement of the GP are significant barriers to uptake. 190 However, GPs are generally positive about the NHS BCSP. 190,191 The British Medical Association also recommends that doctors should be more involved in research and interventions, particularly those aimed at reducing the impact of social determinants on health. 192

Therefore, the third ASCEND intervention tested in a national RCT was the addition of a GPE statement appearing on the NHS BCSP pre-invitation (S1) letter. This was the first RCT to examine the effectiveness of a simple endorsement by an individual’s general practice in the NHS BCSP invitation letter at a national level. Adding the practice name to the pre-invitation (S1) letter was considered to have minimal cost once GPs had agreed to their practice name being used. Some PCTs at the time of the development of this intervention were introducing unevaluated GP interventions as part of their strategy to achieve the Department of Health target for reducing cancer mortality, demonstrating that a simple practice endorsement was likely to be welcomed by users and commissioners.

Development of the general practice endorsement pre-invitation (S1) letter

Recruitment of general practices to endorse the screening offer

To prepare for this intervention it was necessary to seek permission from all current general practices with screening-eligible participants in England (n = 8184) for the NHS BCSP to automatically add their practice name to the pre-invitation (S1) letter received by their patients.

Previous research has not focused on general practices serving disadvantaged populations that tend to have lower levels of engagement in national initiatives. 193–195 In order to establish the best way to approach practices across England, we consulted the PCAG, which provided us with helpful insights into the best way to recruit practices to endorse the pre-invitation. The five NHS BCSP hub directors also provided feedback on recruitment materials developed by the research team.

We anticipated that a modest incentive would engage GPs, especially those from more disadvantaged areas. Effective incentives include realistic information on potential additional consultations about the NHS BCSP made to the general practice (these were found to be marginal in the English NHS BCSP pilot191), feedback on uptake and positivity rates, comparisons with regional and national benchmarks, and provision of promotional material for waiting rooms. The PCAG suggested that offering GPs information about the outcome of the RCT in their area would be an incentive that could realistically be provided by the hubs within their existing capacity.

National recruitment

National recruitment involved sending invitations to the remaining general practices in England that were not involved in the pilot study described above (n = 7934). The recruitment of practices took place over 36 weeks and was completed approximately 2 weeks before the intervention was scheduled to take place.

As with the pilot, practices were sent the invitation letter and information sheet followed by two postal reminders (including the information sheet) after 4 and 8 weeks, as necessary. A third reminder letter was sent at 18 weeks from the initial invitation, without an information sheet, and included an enhanced statement on letters sent to practices located in more deprived postcode areas (quintiles 4 or 5).

The decision to send a third reminder letter was based on the response to the initial invitation and subsequent reminder letters. By the time the second reminder letter had been sent out to practices, a trend appeared to be emerging in the type of practices responding. As seen in Figure 9, practices in more deprived areas were less likely to respond.

FIGURE 9.

Distribution of general practices across IMD quintile (based on practice postcode). Q5 represents the most deprived areas. A total of 1% of practices were not assigned to a quintile owing to lack of data for their practice postcode in the National Statistics Postcode Directory 2007. 197

Previous research has shown that GPs serving patients in more deprived areas are less optimistic about bringing about behavioural change in their patients, which could explain the gradient observed here. 198 To address this, two versions of the third reminder (without an information sheet) were sent out to remaining practices in the UK. This time, practices in deprived areas (quintiles 4 and 5) received the following additional message:

We are particularly keen to include practices that look after patients from more deprived areas because those people are less likely to take part in screening.

Results

Patient and public involvement and engagement

A PCAG comprising professionals including GPs, a practice manager and coapplicants was convened, to assist with the development of the materials used to recruit GPs to endorse the programme and the wording of the endorsement itself. The GPs and practice manager were recruited with help from the Primary Care Research Network for Greater London and through contacts made during the course of the ASCEND programme.

A summary of uptake rates of general practices agreeing to take part in the GPE trial was sent to all general practices that had requested this information during their recruitment to the study.

Summary

This intervention was powered on a very conservative estimate that only 30% of practices would agree to endorse the NHS BCSP and, therefore, we were pleasantly surprised to find that the majority of general practices agreed to do so (80%). The overwhelming response from general practices shows their positive support towards the NHS BCSP.

The high uptake from general practices could be because no additional work was involved in order to take part, as practices simply had to agree that their name could be used on the screening invitation letters. Unlike other research in the UK involving GPE letters, practices did not have to provide an electronic signature or letterhead in order to take part. 37,199

Recruitment letters were sent on NHS BCSP hub letterhead and signed by hub directors, which could have influenced practice response more than a letter from the ASCEND research team. Hub directors already sign all correspondence from the NHS BCSP sent to GPs in their region regarding their patients’ screening pathways.

One invitation and three reminder letters were sent to general practices over a 5-month period, which could have encouraged practices that were too busy or indecisive about responding to earlier letters.

The RCT of the GPE intervention took place in June 2013. Further details are provided in Chapters 9–11.

Background

The value of sending reminders has been well established. A recent meta-analysis of interventions to increase uptake in cancer screening reviewed six separate studies that compared mailing a letter with mailing a letter plus a postal reminder. 196 In all six studies, results were in favour of using mailed reminder letters,196 consistently showing that reminder letters significantly improve uptake. Importantly, research on breast screening attendance has suggested that reminders (telephone or letter) may be helpful in increasing uptake in low-income women,200 particularly if the content of the reminder message is personally relevant and addresses barriers to screening participation, which are known to be socially graded.

Socially graded barriers to cancer screening include lack of awareness of bowel cancer and lack of perceived benefits of bowel cancer screening. There is a strong socioeconomic gradient in cancer awareness. People with a low level of education and a low household income are more likely to have lower awareness of cancer and of the increasing risk of cancer with age. 201–203 This may be particularly true for bowel cancer which, among other cancers, tends to be under-reported in the media relative to the population burden, as shown by a recent content analysis of UK media coverage. 204 Recent evidence has also demonstrated that low awareness of bowel cancer is significantly more prevalent among more deprived groups. 204

In addition to the lack of familiarity with the disease, there is also strong evidence that lower SECs are associated with lack of perceived value of cancer screening. Evidence from the UK FS trial showed that individuals from lower socioeconomic groups tend to perceive the barriers to screening to be higher and the benefits of screening to be lower than do individuals from higher socioeconomic groups. 205 Therefore, for the fourth intervention of the ASCEND study, we developed an ER letter which aimed to increase the personal relevance of the reminder letter by using an additional message to target low awareness of bowel cancer and reinforce the value of cancer screening.

Development of the enhanced reminder letter

We developed the specific messages of the ER letter, consistent with the findings from the workstream 1 focus group concerning beliefs about lack of susceptibility to bowel cancer and an associated failure to understand the potential benefits of screening. In addition, we added a set of reminder-related questions as part of the focus group study in workstream 1. When participants in the focus groups were asked what they thought of the current NHS BCSP reminder (S10) letter, the consensus was that the reminder letter made little impact or impression on them:

So you remember getting a letter – what did you think when you got that letter through?

It didn’t, nothing, I just thought, I’ve not done it [laughs] I’m not doing it, no.

Participants had little recall of receiving the letter:

OK, does anyone else remember getting a reminder letter?

No I never got anything.

Don’t think I did.

When participants did recall receiving the reminder letter, they described putting it to one side or discarding it:

I hadn’t done it, and I still haven’t – got into one of my piles, that’s the trouble and I don’t know which pile it’s in.

FG03 P2

I binned it straightaway, binned it straightaway.

FG06 P7

Introduction

In workstream 2 we developed and tested four intervention strategies designed to target known barriers to uptake in lower socioeconomic groups (see Chapters 5–8). These were (1) ‘gist’ information, a leaflet summarising the key screening information in language suited to respondents with lower health literacy; (2) ‘narrative’ information, a leaflet describing the experiences of people who had taken part in screening; (3) a GPE added to the screening invitation letter; and (4) enhancing the reminder letter by reiterating the screening offer: ER. In workstream 3, we conducted national RCTs for each of these interventions. This chapter describes how the RCTs were carried out.

Methods

Interventions

We were required to ensure that the interventions added to, rather than replaced, the current invitation system in the NHS BCSP, described in Chapter 2. Thus, the first two interventions involved the addition of ‘gist’ and ‘narrative’ information leaflets to screening invitation letters (S1). The remaining two interventions involved modifications to current letters produced by the BCSS. These were a GPE banner added to the invitation letter (S1) and ER intervention added to the reminder letter (S10). Figure 10 shows the stages at which the interventions were to run within the screening programme. For examples of the usual invitation letter (S1) and usual reminder letter (S10) (see Appendices 3 and 7, respectively).

FIGURE 10.

The ASCEND study interventions and the NHS BCSP timeline.

Usual practice in the Bowel Cancer Screening Programme

Men and women aged between 60 and 74 years in England and registered with a GP are invited to be screened for bowel cancer and are sent a gFOBt kit through the post to complete at home. Subjects are invited every 2 years through their regional NHS BCSP hub, which also analyses the tests, sends out test results and contacts diagnostic Screening Centres in its region to arrange for further investigation of subjects with positive gFOBts. On their screening due date, hubs send eligible subjects an invitation letter (S1) that explains that they are due for screening and to expect a gFOBt kit shortly. The kit letter (S9) is posted to them 1 week later and includes a cover letter, information booklet and a gFOBt kit. If after 4 weeks they have not responded, a reminder letter (S10) is posted.

Intervention 1: ‘gist’ information leaflet

The leaflet (see Appendix 13) was pre-printed and included with all the S1 invitation letters on predetermined randomisation dates (see Appendix 33). The trial was run in all five NHS BCSP hubs between 5 and 16 November 2012. The trial took place on 10 working days within that period with an assumption that all the hubs would send S1 invitation letters to their population on every day during that period, resulting in 50 randomised day clusters in each of the five hubs: 25 with usual S1 letters and 25 with the ‘gist’ information leaflet added.

Intervention 2: ‘narrative’ information leaflet

This leaflet (see Appendix 25) was pre-printed and included with all the S1 invitation letters on predetermined randomisation dates. The trial was run in all five NHS BCSP hubs on 10 working days between 4 and 15 March 2013. As with intervention 1, the trial took place on the assumption that all hubs would send S1 invitation letters to their population each day during that period, resulting in 50 randomised day clusters in each of the five hubs: 25 with usual S1 letters and 25 with the ‘narrative’ information leaflet added.

Intervention 3: general practitioner endorsement of invitation (S1) letter

In the months preceding the GPE intervention, we contacted all general practices in England (n = 8184) to ask if they would give permission to allow their practice name to be used on screening invitations during the 4-week study period (recruitment of general practices is described in detail in Chapter 7). Eighty per cent of general practices agreed to take part in the study (Figure 11).

FIGURE 11.

Flow chart showing the possible statuses for intervention 3.

The research team worked closely with HSCIC, the organisation responsible for the design and maintenance of the BCSS. The system identifies the population eligible for screening in each of the five hubs and the hubs are responsible for creating all the letters that are sent to the screening participants and their GPs. For the purpose of our study, HSCIC modified the BCSS to enable selection of invitees belonging to general practices which agreed to endorse the NHS BCSP prior to creation of each invitation letter (S1). In addition, the BCSS took into account the dates when GPE invitations needed to be produced by any of the five hubs. The schema of processes involved within the BCSS and the hubs are shown in Figure 12.

FIGURE 12.

Intervention 3 (GPE) within the BCSS. CFH, Connecting for Health.

The GPE trial ran for 20 working days in each hub, resulting in 10 clusters of invitees receiving an endorsed invitation letter and 10 control clusters in each hub. The intervention took place between 3 and 28 June 2013, and intervention 4 was designed to run 5 weeks after the start of intervention 3 so as to include all non-responding participants.

Intervention 4: enhanced reminder letter

This trial ran for 20 working days in each hub, resulting in 10 clusters of invitees receiving the ER on random days within the trial period. This intervention took place 5 weeks from the start of intervention 3 (GPE), between 8 July and 2 August 2013, in all the hubs in order to achieve the factorial design as shown in Figure 13. This design allowed us to examine the effect of the ER alone and its effect subsequent to GPE. The schema of processes for the ER within the BCSS and the hubs is shown in Figure 14.

FIGURE 13.

Factorial design of interventions 3 (GPE) and 4 (ER).

FIGURE 14.

Intervention 4 (ER) within the BCSS.

Introduction

Chapter 9 described how the four RCTs were carried out, and in this chapter we present the results from the four trials. The gist and narrative trials were run over 10 consecutive days in November 2012 and March 2013, respectively. The GPE and ER RCTs were run over 20 consecutive days in June 2013 and July–August 2013, respectively.

Findings

Trial sample sizes were as follows: gist (n = 163,525), narrative (n = 150,417), GPE (n = 265,434) and ER (n = 168,480); Table 20.

Interventions 1 and 2 each comprised 50 clusters, as planned. Interventions 3 and 4 were supposed to each comprise 100 clusters; however, owing to protocol violations whereby the incorrect randomisation was employed on three occasions, intervention 3 ended up comprising 98 clusters and intervention 4 comprised 99 clusters.

Concurrent initiatives

We identified 65 research initiatives and 101 health promotion activities, of which 14% and 59%, respectively, were localised and specific to bowel cancer screening uptake. Of these, three research initiatives and 27 health promotion activities occurred within a 3-month time frame of each of the ASCEND interventions.

Measuring costs

For the gist and narrative interventions costs of £3106 and £3887, respectively, were incurred for printing and transporting the additional leaflets. These costs were incurred for screening 88,421 and 73,722 participants, and the average incremental cost per screening invitation of providing the interventions was £0.04 and £0.05, respectively.

Using the results from the individual RCTs, it is possible to estimate the potential number of additional cancers and polyps that might be detected if GPE and the ER were implemented nationally across England. We calculated average marginal effects of GPE and the ER from the RCTs and used these to predict their impact on the detection of colorectal adenomas and cancer in the NHS BCSP.

With regard to GPE, a 7% increase in the odds of screening all participants, as found in the multivariable analysis of the trial data, was associated with predictive margins (adjusted average probabilities of uptake) of 0.584 (95% CI 0.581 to 0.586) in the intervention group and 0.574 (95% CI 0.571 to 0.577) in the control group. This translates into a 1.7% relative increase in the probability of screening among all participants (0.584/0.574) and a 1-percentage-point absolute increase (0.584–0.574; the average marginal effect). Although this appears to be a relatively small effect, in absolute terms the impact would be large if it was rolled out nationally given the population size. In the 2013/14 fiscal year, the number invited for screening in the NHS BCSP in England was 3,976,616 (Bowel Cancer Screening System National. National Fiscal Summary 12 June 2015. Claire Nickerson, Public Health England, 2015, personal communication). An average marginal effect of 1% (i.e. 0.010) suggests that if GPE were implemented nationally, then 39,766 extra people each year would be screened. In 2013/14, the positivity rate among the screened population was 1.84% (Bowel Cancer Screening System National. National Fiscal Summary 12 June 2015. Claire Nickerson, Public Health England, 2015, personal communication). Evidence suggests that 83% of people with a positive test result attend a SSP clinic and undergo further investigation212 and, among those who go on to have further investigations, 10.1% will have a CRC and 27.2% will have colorectal adenomatous polyps classed as medium or high risk that require further investigation. 212 Hence, if GPE was implemented nationally this could detect up to an additional 165 people (39,766 × 0.0184 × 0.83 × 0.272) with polyps classed as high or intermediate risk and 61 people (39,766 × 0.0184 × 0.83 × 0.101) with a CRC each year.

For the ER there was also a 7% increase in the odds of screening, this time achieved among those randomised in the ER trial, that is, receiving a reminder letter. This was associated with predictive margins (adjusted average probabilities of uptake) of 0.259 (95% CI 0.255 to 0.265) in the intervention group and 0.250 (95% CI 0.248 to 0.253) in the control group. This implies a 3.6% relative increase in the probability of screening (0.259/0.250) and a 0.9-percentage-point absolute increase (0.259 minus 0.250; the average marginal effect). In the 2013/14 fiscal year, the number of reminder (S10) letters sent in the NHS BCSP in England was 2,144,277 (Bowel Cancer Screening System National. National Fiscal Summary 12 June 2015. Claire Nickerson, Public Health England, 2015, personal communication). An average marginal effect of 0.9% (i.e. 0.009) suggests that if the ER were implemented nationally, then 19,298 extra people each year might be screened. We assume as above that the positivity rate among the screened population was 1.84% in 2013/14, that 83% of people with a positive test result attend a SSP clinic and undergo further investigations and that among those who go on to have further investigations, 10.1% will have a CRC and 27.2% will have colorectal adenomatous polyps classed as medium or high risk requiring further investigation. On this basis, if the ER was implemented nationally it might detect up to an additional 80 people (19,298 × 0.0184 × 0.83 × 0.272) with polyps classed as high or intermediate risk and 30 people (19,298 × 0.0184 × 0.83 × 0.101) with a CRC in England each year.

Introduction

The results presented in Chapter 10 demonstrate that the gist and narrative trials showed no effect on the gradient in uptake (interactions with deprivation quintile: p > 0.05) or overall uptake (gist: OR = 1.03, 95% CI 0.99 to 1.06; p = 0.15; narrative: OR = 1.00, 95% CI 0.96 to 1.03; p = 0.80). In the GPE trial, there was no effect on the gradient but an increase in overall uptake (OR = 1.07, 95% CI 1.04 to 1.10; p < 0.0001). The ER trial showed a significant interaction with deprivation (p < 0.05) with a stronger effect in the most deprived (OR = 1.11, 95% CI 1.04 to 1.20; p = 0.003) than the least deprived quintile (OR = 1.00, 95% CI 0.94 to 1.06; p = 0.98) and higher overall uptake (OR = 1.07, 95% CI 1.03 to 1.11; p < 0.001).

Interpretation

Reducing socioeconomic inequalities in cancer mortality is a priority worldwide. Cancer screening is a major part of a combined effort to bring diagnoses forward to an earlier, more treatable, stage. However, even in the UK, where screening does not incur any cost to the individual, uptake is consistently lower in more socioeconomically deprived groups. 213,214 Together, our four trials constitute the largest evaluation of interventions designed specifically to reduce inequalities in uptake within an organised screening programme. An important strength of the ASCEND trial was that the trials were powered to measure the impact of interventions on SEC gradient in the total eligible population rather than just focusing on disadvantaged groups. Our interventions therefore had the potential to reach a much larger number of non-participants. Use of routinely collected data enabled us to include the whole study population with the exception of a very small group of individuals without IMD scores for their postcodes (see Appendix 36) in our analysis. The lack of attrition accelerates the potential for implementation of these interventions. Each intervention also had a well-established rationale and empirical background, and followed a structured, comprehensive development process. However, only the ER demonstrated a reduction in the SEC gradient in uptake. The gist and narrative interventions showed no effect at all on uptake, while GPE increased uptake overall but did not modify the SEC gradient. None of our interventions promoted an earlier response.

The gist and narrative leaflets were designed to make the screening offer more visible to people with lower literacy skills on the basis of extensive evidence that lower SECs are associated with lower literacy. Both leaflets demonstrated this potential when their effect was evaluated on the basis of knowledge and attitudes, with additional evidence that the narrative leaflet increased intention to attend screening. 171,215 However, in the trials, neither of the leaflets increased bowel cancer screening uptake, either in lower SEC groups or overall. One possible explanation for the discrepancy from the pilot data is the emerging body of evidence indicating that the determinants of intention may differ from the determinants of action and perhaps we influenced intentions rather than actions. 35 Another possible explanation relates to the fact that both leaflets had to be added to the existing invitation/information, rather than being provided as an alternative (because the existing materials are approved nationally to ensure appropriate provision of essential information). Consequently, although the new leaflets were designed to be simple, they nonetheless increased the total mass of written material that participants received and this may have undermined the goal of making the screening offer more visible. We also did not have the resources to translate the leaflets into different languages, which may have limited their impact in more ethnically diverse urban regions, although we saw no hub-specific effects.

A specific issue with the narrative leaflet was that we tried to address negative beliefs about being diagnosed with bowel cancer by presenting two case studies of patients who had been diagnosed early and reported their support of the programme and the relief associated with having their lives saved. However, we acknowledge that these examples may inadvertently work against this effect by reinforcing the link between screening and cancer. This may have overridden the positive messages in the leaflet. Although the pilot study did indicate that the leaflet was associated with increased screening intentions, we were able to observe this effect only among responders to the questionnaire. Our national trial of GPE significantly increased uptake overall. The effect size was smaller than in many previous studies,36,196,216,217 but this was probably because most of those had used letters directly from the GP or had an individual GP’s signature on the letter. In the NHS BCSP, all invitation letters come from the hubs; therefore, the only practical option was to include a banner noting that the individual’s general practice supported the programme, but without individual GPs’ names or signatures. It would not be surprising if this diluted the impact. However, given the exceptionally high level of agreement by general practices to endorse the NHS BCSP, the small one-off cost to modify the standard invitation letter within the NHS BCSP IT system (to adjust for any recent changes in practice name) and the zero marginal cost per person screened, we recommend that the NHS BCSP consider adding GPE to the screening invitation letter.

Because previous studies had shown effects of GPE in low-income groups (e.g. Ahmed et al. 218), we had hypothesised that it might have a stronger effect in lower than in higher SEC groups. No previous study had been powered to examine effects on the SEC gradient and the size of the present trial provides a definitive negative result, at least with the format of GPE that was used.

The one intervention that reduced the SEC gradient was the ER. Our aim was to offer anyone who may not have engaged with the original materials an additional opportunity to see the screening offer. Unlike the gist and narrative interventions, which tried to achieve this with an additional leaflet, the ‘enhancement’ was incorporated into the one-page reminder letter. The information pack which contained this letter did not include any of the other usual information materials (e.g. ‘The Facts’ booklet) and was therefore much thinner than the invitation letter used in the other trials. It is likely that this increased its visibility and impact. Although the change in the gradient was small (as was the effect on overall uptake), this intervention was also virtually ‘cost free’ and, therefore, offers a practical way for the screening programme to achieve a reduction in the SEC gradient.

The ASCEND programme inevitably had limitations in terms of the range and types of interventions that were tested. People from socioeconomically deprived backgrounds are likely to be struggling with multiple social and economic challenges and this could make it difficult for them to prioritise cancer screening, but these ‘upstream’ issues are never going to be addressed by minor variations in the format of the screening offer. Similar observations have also been made in other NHS BCSPs where addressing psychosocial variables through written materials has also failed. 196 Nonetheless, we believe that ensuring that the screening offer is not only mailed to all eligible adults, but is equally accessible to respondents at all levels of literacy, is an obligation of the NHS screening programmes. We also did not address broader attitudes to cancer outcomes that could be important. For example, cancer fatalism is known to be higher in lower SEC groups and has been shown to be associated with later stage of diagnosis;219 however, fatalism is not easily modified with simple written materials. There were also other downstream barriers that we did not address, of which the most well established is ‘faecal aversion’. The gFOBt is widely regarded as unpleasant and some individuals are likely to be more averse to contact with faecal material than others,220 although there is no existing evidence that this barrier is socially graded. In contrast, the need to store the gFOBt kit between samples could be a socioeconomically graded barrier because it requires privacy and privacy may be limited for people living in less advantaged circumstances. In the context of the ASCEND study, we were unable to identify ways of addressing this barrier, but it is possible that if the NHS BCSP implements the faecal immunochemical test (FIT), which typically requires only one sample, inequalities in participation would be reduced. Use of FIT has recently been shown to reduce the SEC gradient in uptake (compared with gFOBt) as part of an evaluation of FIT in the Scottish NHS BCSP. 221

One issue that should be considered is whether or not individuals who did not take up the offer are making a ‘rational’ decision (e.g. judging that screening would not offer benefit given their personal circumstances). The lower perceived life expectancy in lower SEC groups222 has been put forward as one explanation for differential engagement in activities that produce benefit only in the distant future. 31 Contrary to this view is evidence that ‘non-attenders’ often express interest in screening once they have discussed it in a one-to-one setting,223 suggesting that, when the information is presented verbally with opportunities to clarify, screening is widely perceived to be advantageous. In addition, inequalities in breast screening uptake (involving women of a similar age) are much lower than for bowel cancer screening in women, with an absolute difference from the least to most deprived IMD quintile of only 10% in one study,213 suggesting that screening per se is not the problem.

Although the over-riding message of this study is the challenge of shifting the gradient in screening participation within the context of a national screening programme, the research design in which strategies to be tested are embedded in routine programme delivery provides a model for future research. There may also be scope to improve the impact of the interventions. The gist and narrative leaflets may have been ‘swamped’ among other elements of the mailing. One alternative could be to supply the necessary screening information in smaller ‘bites’ by integrating additional communication points into the screening pathway. There may also be scope for additional reminder letters. Given that successive reminders would, through a process of elimination, target an increasingly deprived population, this should also reduce the uptake gradient. More controversially, it may be timely to consider adding direct contact with health professionals or trained lay experts to present the case for screening and support informed decision-making for some population groups. ‘Patient navigation’ has been shown to increase uptake across a number of cancer screening programmes and has been designed specifically with low literacy and socially disadvantaged groups in mind. 223

In conclusion, three out of four trials of interventions aimed at tackling inequalities in screening uptake failed to reduce the SEC gradient. An ER letter was the only strategy to significantly reduce the gradient, while GPE increased overall uptake. Given their minimal cost, these interventions could be implemented immediately to support the enhanced and equitable delivery of cancer screening within the NHS BCSP. The results of these trials are testament to the difficulty of modifying inequalities in screening within an organised programme, but they highlight the importance of continuing to research effective strategies to achieve equity in early diagnosis of cancer.

Comparison with other studies

The effectiveness of the ER letter in reducing the socioeconomic gradient in uptake of a public health intervention is significant because such an effect has rarely (if ever) been demonstrated. Cesar Victora’s ‘inverse equity hypothesis’, which predicts that new public health interventions initially reach those of higher socioeconomic status and only later affect the poor when the affluent have achieved new minimum achievable levels for morbidity, has been confirmed internationally. 224 Our results are therefore highly noteworthy.

The results of the ER could be explained in relation to insights gained from our own qualitative work (workstream 1), previous evidence and health behaviour theory. For example, there was strong evidence that reminders significantly increase uptake of cancer screening. 203,225 However, workstream 1 focus group participants consistently reported not recognising the letter. The text at the top of the letter was therefore designed to clearly state the purpose and may have increased its personal relevance (‘A reminder to you’). The additional text at the bottom of the letter aimed to further increase the urgency of the letter by addressing well-established predictors of CRC screening uptake. The first sentence clearly stated the importance of CRC screening as a way to reduce risk of CRC. Perceived risk has been extensively studied as a predictor of cancer screening. 226–228 Importantly, the message was designed to be simple and direct about the increased risk of CRC without using complex statistical information following the sample principles underlying the development of the gist leaflet and thereby increasing its effectiveness among low-literate individuals. 143 The second sentence addressed response efficacy (i.e. the belief that screening is effective), which is a key construct in the Health Belief Model, which has been found useful in trying to predict CRC screening uptake. 229 Third, we reduced perceived barriers to screening by affirming that ‘it is never too late to screen’ and increased self-efficacy by offering guidance about how to seek further guidance.

Future research should focus on which of these aspects had the strongest impact, particularly among socioeconomically deprived individuals.

The gist RCT was the first trial of information materials guided by FTT. Several studies have shown that people, particularly older adults, have a preference for extracting gist-like representations from health information. 93,94 However, there have been no trials of whether or not materials developed with these preferences in mind have an impact on screening knowledge or behaviour. Our null results add to the mixed evidence for behaviour change interventions using educational materials. 230 Three trials of mailed materials focusing on barriers to screening uptake reported an increase in uptake: one in FS screening231 and two in gFOBt screening. 178,232 Two other trials observed no effect37,233 and one saw reduced uptake with mailed materials. 234 A recent US-based study also failed to demonstrate a statistically significant increase in uptake associated with adding an educational pamphlet, video and simplified gFOBt kit instruction sheet to usual care materials. 235

The narrative RCT was the first trial to incorporate personal quotations and stories regarding the NHS BCSP experience into information material. Presenting information in a narrative format is becoming a popular form of health communication and has shown encouraging results in the science literature. 156,158 Dillard et al. 162 found that by integrating a short narrative to non-narrative factual information, the anticipated impact of barriers to screening (via colonoscopy) was reduced, while perceived personal risk and intention to have a colonoscopy were enhanced. 162 The inclusion of a bowel cancer screening narrative has also been found to increase colonoscopy attendance fourfold when compared with providing non-narrative information only. 165 Until now, no research has focused on narratives in relation to screening via gFOBt. The evaluation/pilot trial of the current narrative leaflet indicated an increase in intention and positive outcomes on factors predictive of screening intention, including enhanced personal risk and reduced impact of disgust as a barrier. 171 However, within the RCT, this intention did not translate to an increase in screening attendance, again adding to the mixed evidence available on the effectiveness of health education interventions. Another reason why both gist and narrative leaflets did not show the promised effect is that the development of such interventions is limited to a highly selected sample of people willing to participate in research. This was true of both studies pre-testing the effectiveness of our leaflets despite a concerted effort to develop links with community organisations and by purposefully selecting primary care practices serving deprived areas.

The GPE intervention was successful in gaining approval from four out of five general practices, which is an unprecedented general practice participation rate compared with other studies, allowing us to randomise over 260,000 individuals from 6480 general practices. By comparison, the largest study of GPE to date randomised 2400 individuals. 36 Importantly, this large sample size allowed us to be the first study to address the question of whether or not GPE that has been shown to positively influence uptake also has the ability to reduce the socioeconomic gradient. The ability to conduct a study of GPE on such a large scale meant that we had to curtail the requirements on general practices. Furthermore, integrating the GPE in an existing letter severely reduced the number of characters used in the message. Both of these issues could have adversely affected the strength and visibility of the message.

Taken together, these results indicate that despite a strong theoretical background and extensive pre-testing, the design of effective behavioural interventions is challenging.

Methodological strengths

Among the strengths of our trial were its national coverage, substantial power to detect small differences in uptake, and an intervention, which, if effective, could easily and cost-effectively be incorporated into the existing NHS BCSP. We used novel, innovative methods to develop a gist leaflet that enhanced comprehension and carried out extensive user testing and piloting to demonstrate its accessibility to adults with basic literacy skills. Similarly, the narrative leaflet was designed by drawing on the expertise of colleagues in social marketing, health psychology and public health promotion. The final layout and content were established through focus groups and one-to-one interviews with members of the public, with subsequent piloting in the community confirming its acceptability.

Research limitations

Unlike the narrative and the gist pilot, it was not possible to pre-test the impact of the GPE and the ER interventions. In the case of the GPE, the main issue to be addressed during workstream 2 was that of recruiting general practices. In addition, our ability to manipulate the length and content of the message was severely limited by requirements stipulated by the NHS BCSP. In the case of the ER letter it was impossible to pre-test its impact on a population outside the screening programme. It is therefore difficult to ascertain the degree to which people perceived these interventions (e.g. whether or not they noticed them and accepted or rejected their respective messages). Given that all of these interventions were run in a routine screening programme, we were also prevented from conducting any further evaluation of the interventions among people who had been part of the interventions. Doing so would have required seeking consent from individuals and would have been dominated by individuals who had participated in screening.

These trials had limitations. The NHS BCSP hub directors were clear that parallel RCTs and individual randomisation of subjects for all interventions could not be performed for feasibility reasons. Therefore, cluster randomised trials were adopted as the strongest alternative. Cluster randomised trials can have compromised statistical efficiency owing to clustering, which increases the sample size required to achieve appropriate power. 236 This was addressed in our sample size calculation and our target was surpassed in all trials.

A further limitation is the possibility that the study groups became contaminated, such that individuals in the control groups were exposed to the interventions. Although this limitation is noted, it would also have applied to a parallel randomised trial.

Although it is possible that localised initiatives may have affected uptake rates in specific regions, it is considered unlikely that they would have confounded the ASCEND intervention results overall, primarily because it is improbable that concurrent interventions would occur on the same alternate days as each intervention.

In addition, our findings may have been influenced by other factors operating within a cluster affecting the outcome. We surveyed the number and location of health promotion activities occurring during the period of the trials, but we cannot rule out the possibility that these reduced the effectiveness of the interventions.

Finally, our study did not include evaluation of the sociopsychological determinants of the behaviour of individuals during the decision-making period. This explains the limitations outlined above, such as our focus on behavioural intentions rather than actions and our inability to obtain an in-depth and comprehensive understanding of the determinants of social variations in decision-making processes in real time. It is possible that ethnographic case studies of everyday practices through sustained observation within different sociocultural contexts in addition to semistructured interviews conducted over the decision-making time period could yield important insights. However, it should also be recognised that the completion of the screening test (and, therefore, the final decision-making step) takes place in the privacy of one’s home (making observation and interview data more difficult and resource intensive to obtain) and that frank interview responses might be influenced by sociocultural norms on the appropriateness of discussing an intimate topic. Furthermore, observation and explicit exploration of decision-making (which might otherwise be exclusively implicit) could influence the decision made.

Patient and public involvement

Our Patient Representative, Mr Roger Band, reviewed and commented on the results of the all the trials.

Conclusion

The four largest trials of interventions aimed at reducing socioeconomic inequalities in screening uptake within an organised NHS BCSP failed to substantially affect the gradient. However, the ability of the simple reminder message to achieve the hypothesised reduction in inequalities is a highly notable achievement that has been rarely (if ever) documented in the published literature. Furthermore, the effectiveness of gist and narrative information leaflets when used alone are unknown and should be explored as part of alternative communication opportunities.

These results highlight the difficulty of modifying inequalities in screening uptake through easily implementable, cost-effective, interventions that respect informed decision-making.

Contributions of authors

Rosalind Raine, Wendy Atkin and Jane Wardle conceived the idea for this study and led all components of workstreams 1, 2 and 3, respectively.

Rosalind Raine led the research team (Jane Wardle, Wendy Atkin, Stephen Duffy, Stephen Morris, Christian Von Wagner, Allan Hackshaw, Stephen P Halloran, Sandra Rainbow, Samuel G Smith, Graham Handley, Richard Logan, Neil Stubbs, Austin Obichere, Roger Band) which designed the successful application for funding. As the Chief Investigator and guarantor, Rosalind Raine managed the study overall and has final responsibility for the analysis and report content.

Christian von Wagner, Ines Kralj-Hans, Lesley McGregor, Cecily Palmer, Samuel G Smith, Mary Thomas, Rosemary Howe and Gemma Vart contributed to study design, review of the literature, recruitment of participants, data collection, analysis, interpretation and drafting of the chapters relating to the research component that they were involved with across workstreams.

Rosalind Raine, Christian von Wagner, Lesley McGregor, Cecily Palmer, Samuel G Smith, Mary Thomas and Rosemary Howe prepared the first draft of this report.

Stephen Duffy and Allan Hackshaw collaborated in the funding application and were responsible for the statistical aspects of the study, including involvement in the study design, analysis and interpretation.

Nicholas Counsell and Sue Moss conducted statistical analyses (workstream 3).

Roger Band provided guidance from a patient perspective throughout the research programme.

Samuel G Smith, Stephen P Halloran, Neil Stubbs, Graham Handley, Richard Logan, Sandra Rainbow, Austin Obichere and Stephen Smith provided NHS BCSP-specific and clinical expertise throughout the research programme.

Julia Snowball prepared the downloaded trial data.

Stephen Morris and Francesca Solmi conducted the health economic analyses (workstream 3).

All authors contributed to subsequent drafts, approved the final draft and contributed to analytic design, interpretation and drafting of this report.

Publications and presentations (up to March 2015)

Data sharing statement

All available data can be obtained from the corresponding author, Professor Rosalind Raine.

Disclaimers

This report presents independent research funded by the National Institute for Health Research (NIHR). The views and opinions expressed by authors in this publication are those of the authors and do not necessarily reflect those of the NHS, the NIHR, CCF, NETSCC, PGfAR or the Department of Health. If there are verbatim quotations included in this publication the views and opinions expressed by the interviewees are those of the interviewees and do not necessarily reflect those of the authors, those of the NHS, the NIHR, NETSCC, the PGfAR programme or the Department of Health.

The screening pathway

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