The Family Nurse Partnership to reduce maltreatment and improve child health and development in young children: the BB:2 6 routine data-linkage follow-up to earlier RCT

Article history

The research reported in this issue of the journal was funded by the PHR programme as project number 11/3002/11. The contractual start date was in February 2014. The final report began editorial review in August 2019 and was accepted for publication in May 2020. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The PHR 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.

Personal dedication

Our work aims to improve the life chances of babies. All babies are precious. Their wonderful potential, their joy and their sorrows can sometimes get lost when quantified statistically. It is often our personal knowledge that brings meaning to such numbers. I dedicate this report to my own grand-daughter, Luna Alice Atkins, who left us this year aged only three days old. She will forever remain precious to us and her life will always have meaning. Michael Robling, 2020

Copyright statement

© Queen’s Printer and Controller of HMSO 2021. This work was produced by Robling et al. under the terms of a commissioning contract issued by the Secretary of State for Health and Social Care. 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.

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Summary

The Building Blocks: 2–6 years (BB:2–6) study has followed up the cohort of mothers originally recruited to the Building Blocks (BB) trial of the Family Nurse Partnership (FNP) in England, BB: 0–2 years (BB:0–2). Using routine data drawn from across public sector providers to augment trial data, the study offers a unique opportunity to evaluate the medium-term outcomes of the FNP as a preventative intervention to reduce child maltreatment in England. This chapter provides an introduction to the principal clinical domain addressed by the BB:2–6 study; presents previous research on the specialist home-visiting programme both in the UK and internationally; and provides a rationale and description for the current study aims and objectives.

Maltreatment

Maltreatment involves acts of omission (neglect) or commission (abuse), often by caregivers who either threaten to risk, risk or actually cause harm to a child. 2 Abuse may be physical, emotional or sexual. Neglect represents persistent failure to meet a child’s basic physical or psychological needs, often resulting in serious impairment of the child’s health or development. 2 Neglect may involve failing to do any of the following: protect a child from physical and emotional harm or danger, ensure adequate supervision or ensure access to appropriate medical care. In the financial year ending 31 March 2018 in England, there were 655,630 referrals to children’s social care (CSC) services (relating to 581,280 children, an average of 1.13 referrals per child), 406,770 children were starting an episode of need (an overall rate of 341.0 per 10,000) and 53,790 children became subject to a child protection plan. 3 A child protection plan is a plan drawn up by the local authority detailing how the child can be supported. The most common reason for a child to become subject to a child protection plan was neglect (48.0%), followed by emotional abuse (35.1%). 3

In the UK, preventing maltreatment is an important focus of government concern. The Children Act 19894 specifies agencies’ responsibilities to co-operate in the interests of vulnerable children, for children in need (section 17) and children suffering or likely to suffer from significant harm (section 47). A child in need (CIN) is defined as a child who is unlikely to achieve or maintain a reasonable level of health or development, a child whose health and development is likely to be significantly or further impaired without the provision of services, or a child who is disabled. 4 Local authority provisions may include supervision of activities; financial help; and/or provision of family accommodation, respite or home help, in addition to advice and guidance from social workers.

Specialist home visiting: the Family Nurse Partnership

There has been an increasing emphasis on the primary prevention of child maltreatment, including interventions directed at general populations and those targeting high-risk groups. The US Department of Health and Human Services’ Home Visiting Evidence and Effectiveness review5 maintains an ongoing assessment of evidence on home visiting as a preventative intervention. One such preventative home-visiting approach to reducing maltreatment is the FNP programme [developed in the USA as the Nurse–Family Partnership (NFP)], with three overarching goals: to improve birth outcomes; to improve child health and development, including reducing maltreatment; and to promote the economic self-sufficiency of mothers. 6 The programme aims to promote sensitive and competent caregiving and to reduce maltreatment through activities such as education about child development, modelling sensitive parent–child interaction, and guidance on accessing appropriate child care. The NFP is one of three preventative programmes shown to be effective in preventing maltreatment;7 in the USA, it is delivered in 42 states (plus the US Virgin Islands). 8 In three US trials (in Elmira, NY; Memphis, TN; and Denver, CO),9–11 the NFP has demonstrated improvements in prenatal health behaviours and birth outcomes; improvements in sensitive child care; reductions in child injuries, abuse and neglect; improvements in maternal life course (e.g. greater workforce participation); and improvements in child and adolescent functioning. The NFP has shown greatest impact on those at greater risk, and, although there is no net saving for married women or those of higher socioeconomic status, for low-income and unmarried mothers, the cost of the programme was recovered by a child’s fourth birthday.

In the first US trial,9 in the subgroup of poor unmarried teenage mothers, by the age of 2 years, there was verified abuse/neglect in 19% of control children, compared with 4% in the NFP group, and for the NFP group a 56% relative reduction in emergency department attendance for injuries and ingestions during the second year of life compared with the control group. Among the subgroup of children (56 families) with a state-verified report of maltreatment by age 4 years, the NFP group of children exhibited fewer risks for harm than the control group (e.g. fewer attendances for injuries/ingestions, safer home environment). 12 In the 15 years after birth, mothers as perpetrators of abuse were less common in the NFP arm than in the control arm (log incidence of 0.29 vs. 0.54, respectively; p < 0.001), an effect even greater for the most vulnerable subgroup: mothers of low socioeconomic status who were unmarried (log incidence of 0.11, compared with 0.53 for the control arm; p < 0.001). 13 Although the beneficial impact on state-verified first-time reports of maltreatment is generally experienced after age 5 years, the difference is seen earlier (age 3 years) for the most vulnerable subgroup of poor unmarried mothers of the NFP trials.

Common to other home-visiting programmes, the NFP aims to address several related child and maternal outcomes, and a key objective is to promote child development and school readiness. This can be supported by programme elements such as educating parents about child development, promoting positive parent–child interactions and linking families to additional specialist support. US trials of the NFP found improvements in mathematics (among mothers with low resource) and mental processing (whole sample and low resource) at age 6 years, and in reading and mathematics at ages 9 and 12 years. 14,15 Language skills were also improved at 34 and 48 months for children of mothers with low resource. 16,17

Justification/rationale for the study

This study aimed to provide evidence for the medium-term effectiveness and costs of one of the most promising early-intervention programmes for reducing the risk of child maltreatment in a targeted vulnerable population. This would inform policy about whether or not to continue implementing a programme for which there is limited existing UK evidence for effectiveness. Although we generated evidence related to short-term effects in the BB:0–2 trial (i.e. up to the point when families graduate from the programme before or at their first child’s second birthday), the recognised potential programme benefits (in particular for child maltreatment) have largely been demonstrated only in the longer term. This study presented a unique opportunity to extend learning from the trial by using the existing outcome data in combination with newly arising routinely recorded data.

Research aims and objectives

Given the evidence from both US and Dutch trials of programme benefit for families arising in the 4-year period following the NFP graduation, we aimed to determine the medium-term impact of the FNP on child maltreatment outcomes and key indicators of neglect (e.g. injuries and ingestions), child development and educational outcomes, and other hypothesised programme impacts measurable through routine data.

Research objectives

In the BB:2–6 study, we used existing trial cohort data linked to routinely collected national data sets to assess the medium-term impact of the FNP on objective measures and indicators of child maltreatment outcomes; child health, development and educational outcomes; and other programme-relevant outcomes.

Study design

The data-linkage study generated a linked anonymised database hosted by a data safe haven. We followed up participant mothers and children from BB:0–2 for a further 5 years using routine data only. Health, education and social care data from a range of routine public sector sources were retrieved and linked to existing trial cohort data on an individual level. This enabled children and mothers to be followed until the child reached Key Stage 1 (KS1), the 2 years of schooling when pupils are aged between 5 and 7 years. Participants were recruited to the BB:0–2 trial between June 2009 and July 2010; therefore, the follow-up for all participants was completed in May 2018, when the youngest children completed their KS1 assessment. A summary of the data sources is provided in Appendix 2, Table 26.

Study participants

In the BB:0–2 trial, we recruited nulliparous women aged ≤ 19 years, living in one of 18 local authority FNP catchment areas, who were at < 25 weeks’ gestation, who were able to provide consent and who could engage with the FNP in English. 21 Women expecting multiple births and those with a previous pregnancy ending in miscarriage, stillbirth or termination were eligible. Women planning to have their child adopted or to move outside the FNP catchment area for > 3 months were not eligible. Women and their first child (or twins, if relevant) who were not mandatorily withdrawn from the BB:0–2 trial (e.g. owing to miscarriage, stillbirth, infant death or adoption), or who did not electively withdraw (including their consent for use of their data) were eligible to be included in BB:2–6 study.

Outcomes

The study follows the multimethod multisource approach to maltreatment research, which considers an outcome continuum from child maltreatment to family wellness. 33,34 As we have access to routine data, which are a record of professionally determined outcomes, our data are primarily objective (in that we are not using parent-reported proxy outcomes). 35 Although professional decision-making will involve subjective assessment, our distinction is between assessments that are established by professionals and those directly involving parents. We have also distinguished between objective measures of maltreatment assessed in the CSC and associated measures of maltreatment assessed in health care. Although a primary outcome is identified, interpretation will collectively assess evidence for maltreatment.

Data sets and data providers

Dissent model

Data access and storage

Data were requested in two stages: (1) for the pilot phase as part of the feasibility work and (2) the main data request. When the study started in 2014, the children were only 3 years of age, thus providing the opportunity for the pilot phase to ensure that we could access the data, link the records and address the primary and secondary outcomes using the data received. 31 Data were requested in autumn 2014 for data from NHS Digital and the NPD and then again in summer 2017 for the main extract. Data were requested from the Abortion Statistics Team in autumn 2017. The identifiers used to match the BB:2–6 study participants to each data provider are shown in Appendix 2, Table 28.

We used a data safe haven, the Secure Anonymised Information Linkage (SAIL) databank, to receive all data sent from data providers, replace the participant identifier with a new anonymous linking field (ALF) and store the corresponding identifier in a separate encrypted password-protected file. 48 All data held in SAIL must not be identifiable; therefore, the study team went through a de-identification and standardisation process to ensure that all variables (e.g. date of birth) were amended to be non-disclosive (e.g. week of birth) or removed from the data set prior to sending. Figure 1 depicts the data flow between data providers and the data safe haven. Participants are not identifiable to the study team, or to the SAIL analyst, but incoming data sets from all data providers could be linked at the individual level using the ALF. The study team have controlled remote access to these data, thus ensuring the security of the pseudonymised database. 49 All data cleaning and analyses were carried out via the remote portal by the study data manager(s), statistician and health economist.

FIGURE 1.

Final model of data flow, storage and access used in BB:2–6. a, De-identification and standardisation applied (e.g. date of birth to week of birth). b, Data providers confirm matching of BB/NHS Digital/ONS/DfE/DHSC IDs. ID, identifier.

Governance

Following REC approval (reference number 14/WA10062) and section 251 support (CAG number 10-08(b)/2014), we could submit data request applications to the DfE, NHS Digital and the DHSC. To satisfy the requirements of the section 251 support and NHS Digital contract, the (then) information governance toolkit self-assessment50 (commissioned by the DHSC for NHS Digital to develop and maintain) was required. This is now known as the Data Security and Protection Toolkit. This organisation-level assessment provides reassurance of satisfactory information governance within the host research organisation. Both the section 251 support and the Data Security and Protection Toolkit are assessed and renewed on an annual basis. The opt-out model was also required to satisfy the section 251 support, as well as the DfE assessment of compliance with principle 1 of the Data Protection Act 1998. 51 Governance and data provider requirements prior to application approval are shown in Figure 2.

FIGURE 2.

Governance and data provider requirements prior to application approval. IG, information governance. The shading represents the starting point for each activity. The dotted-line boxes indicate the project team roles.

Statistical analysis

Economic analysis

A health economics analysis was undertaken using the routinely collected data available from the BB:2–6 study.

The evaluation consisted of:

• a description of the resource use and costs associated with the FNP during the BB:2–6 study

• a cost–consequences analysis (CCA) of the FNP based on the outcomes reported in the BB:2–6 study

• a summary of the total known health-care costs of the FNP over the full 6-year follow-up period, by summarising the costs associated with the FNP.

Aims/objectives

The aims of the pilot phase were (1) to establish and verify the governance, regulatory and logistical arrangements for linking data sets and (2) to prepare and assess the suitability of data for answering the research objectives and planned analysis.

Methods

Obtaining data from data providers

We requested data from NHS Digital and the DfE (NPD) for a proportion of the BB:2–6 sample. For NHS Digital, this included data from trial entry of the first mother (June 2009) to 31 March 2015. Local authority safeguarding data, accessed via the modular NPD data sets, were requested to 31 March 2014, and education data were requested from the NPD to other end points in 2014. Appendix 3, Table 33, summarises the time periods requested for each data set. Data sets are released annually, but at different points throughout the year, by both NHS Digital and the NPD; therefore, the data were requested to allow the greatest number of years possible at the time of request.

We did not include participants electively withdrawn from the BB:0–2 trial in the pilot cohort sent for matching, as further tracing was ongoing at the time of data transfer. In addition, we did not send a small number of the main cohort for matching for the same reason (i.e. tracing indicated a different date of birth or sex, which needed further investigation). Figure 3 outlines participants’ progress through the trial processes, including the numbers of participants involved at each stage. It also includes the estimations of sample numbers at the time pending the tracing.

FIGURE 3.

Participant flow diagram showing numbers of mothers and children sent for matching and successfully linked in the pilot and main study phases. C, children; EW, elective withdrawals; M, mothers.

We used the participant identifier from the BB:0–2 trial to identify both mother and child. This was appended to all records sent to NHS Digital and the NPD for matching. We stated in the approved data access applications to both data providers that participant identifiers would be retained while stripping all other identifiable data from the records sent to SAIL (data safe haven) from the data provider. SAIL replaced the participant identifiers with ALFs to ensure that all records were anonymised and not identifiable to the study team by the participant identifiers. We checked that the numbers of records sent to each data provider, received by SAIL and then available to the study team were consistent and could be linked in the SAIL portal.

Results

Summary

Overall, we were satisfied that the main study objectives were achievable, although some secondary outcome and exploratory analyses may be restricted by missing data or small numbers. The data flows were acceptable to data providers; it was possible to access data from all providers requested and match rates were high. The time taken to receive data was identified as an ongoing risk; this reflected the timetable for submitting the renewal application to all data providers.

Study population

The study population following the BB:0–2 trial and the tracing and matching process is shown in Figure 4. Trial recruitment to the BB:0–2 trial started in June 2009 and ended in July 2010; 1645 women were recruited and randomised from 18 sites across England, and 1618 women completed a baseline interview and provided ongoing consent for data usage. Five women were ineligible and 78 were mandatory withdrawals, mainly due to fetal or infant death or adoption. Further details regarding mandatory withdrawals can be found in the trial report. 32 The 110 women who electively withdrew during the trial were given the opportunity to opt out from further data usage; 16 women removed consent for any further contact. Thus, 94 women who had electively withdrawn from the BB:0–2 trial were included and their details sent for tracing alongside the remaining 1452 mothers (a total of 1546 mother–child dyads) to update contact details to improve the matching process. One dyad was subsequently removed, and the remaining 1545 were contacted by letter, e-mail or text, of whom eight dissented from having their records linked. A total of 107 children had missing information that was needed to match to the NPD and NHS Digital data sets; they were manually traced by the NHS Digital tracing service to update one or more identifiers.

FIGURE 4.

Flow diagram of the tracing and matching process. C, child; EW, elective withdrawals; M, mother; MW, mandatory withdrawals.

A total of 1537 mothers and 1547 children (1517 singletons and 15 sets of twins) were sent to the NPD and NHS Digital for matching. These formed the population for the BB:2–6 study. The numbers of mothers and children matched to and returned for analysis by data set are presented in Table 2. Owing to having discontinued their education, very few mothers, compared with children, were matched to any NPD data set (19% vs. 97%, respectively); these events were based mainly on the CIN data set. A high proportion of mothers and children were matched to the NHS Digital data set (> 97%). In addition, 1532 mothers’ records were supplied to and matched to abortions data by the DHSC; five mothers did not have a postcode and records were not supplied for matching. In the NHS Digital data sets, one set of twins was allocated the same HES identifier and all records relating to both were identical. One set of records was considered a duplicate and excluded from all analyses using NHS Digital data. This was not the case for NPD data sets, in which NHS numbers were not used in the matching, and we assume that records were unique to the child.

Descriptive analysis by trial arm

The Consolidated Standards of Reporting Trials (CONSORT) flow diagram (Figure 5) shows the numbers in the BB:2–6 study by trial arm. For all participants (mothers and children) sent for matching, descriptive statistics are used to summarise the same baseline variables. No marked differences are observed between the trial arms in the characteristics identified in Table 6. Although the study populations will vary depending on which data provider is examined (NHS Digital or the NPD), because of the small number who are not matched to both data sources, there is a minimal risk of potential bias.

FIGURE 5.

The CONSORT flow diagram. C, child; EW, elective withdrawals; M, mother; MW, mandatory withdrawals.

TABLE 6 - Maternal and baby characteristics for mothers (n = 1537) and children (n = 1547) sent for matching, by trial arm

EET, employment, education or training; IMD, Index of Multiple Deprivation; SD, standard deviation.

Applicable only to those whose age at the end of the previous academic year at time of baseline interview was > 16 years.

Higher IMD score indicated more deprivation. Mean IMD score for England in 2010 was 21.67. 69

Higher score indicates higher level of self-efficacy.

Characteristic	Trial arm
	FNP	Usual care
Mothers	N = 766	N = 771
Maternal age at recruitment (years), median (25th to 75th centile)	17.9 (17.0 to 18.8)	17.9 (16.9 to 18.8)
Ethnicity, n (%)
White	675 (88.1)	680 (88.2)
Mixed	44 (5.7)	38 (4.9)
Asian (excluding Chinese)	15 (2.0)	10 (1.3)
Black	29 (3.8)	40 (5.2)
Chinese or other	< 5	< 5
Relationship status with baby’s father, n (%)
Married	6 (0.8)	10 (1.3)
Separated	72 (9.4)	78 (10.1)
Closely involved/boyfriend	582 (76.0)	586 (76.0)
Just friends	106 (13.8)	97 (12.6)
NEET status,a n (%)
Yes (i.e. NEET)	315 (41.1)	319 (41.4)
No (i.e. in EET)	345 (45.0)	333 (43.2)
Participant academic age of < 16 years at interview	104 (13.6)	117 (15.2)
Missing	2 (0.3)	2 (0.3)
IMD overall score,b median (25th to 75th centile)	38.1 (24.6 to 52.6); n = 760	38.1 (25.5 to 51.6); n = 765
Generalised self-efficacy scale (score 10–40),c median (25th to 75th centile)	30.0 (28.0 to 33.0); n = 764	30.0 (27.0 to 32.0); n = 769
Adaptive functioning: difficulty in at least one basic skill, n (%)
Yes	213 (27.8)	184 (23.9)
No	552 (72.2)	586 (76.1)
Missing	1 (0.1)	1 (0.1)
Adaptive functioning: had three or fewer life skills (out of five), n (%)
Yes	185 (24.2)	218 (28.3)
No	578 (75.8)	551 (71.7)
Missing	3 (0.4)	2 (0.3)
Adaptive functioning: at least one burden, n (%)
Yes	214 (28.2)	237 (30.9)
No	545 (71.8)	530 (69.1)
Missing	7 (0.9)	4 (0.5)
Cigarette smoking, participant self-reported, n (%)
Ever smoked
Yes	615 (80.3)	612 (79.4)
No	151 (19.7)	159 (20.6)
Children	N = 773	N = 774
Sex
Male, n (%)	381 (49.3)	406 (52.5)
Female, n (%)	392 (50.7)	367 (47.5)
Missing (n)	0	1
Birthweight (g), mean (SD)	3223.81 (606.0)	3215.52 (555.56)
Missing (n)	49	22
Neonatal unit admission (direct or subsequent)
Yes, n (%)	76 (10.6)	66 (8.8)
No, n (%)	640 (89.4)	683 (91.2)
Missing (n)	57	25

Objective measures of maltreatment

This chapter describes the effectiveness of the FNP programme in reducing objectively measured medium-term maltreatment outcomes, when compared with usually provided health and social care alone, over the first 6 years of a child’s life. These outcomes of maltreatment are presented in sequential order, starting with the initial referral to CSC, CIN status (primary outcome), whether or not the child was subject to a CPP, and the looked-after status of the child. The denominator for all analyses is the 1507 children who were matched to any NPD data set (FNP, 760 children; usual care, 747 children). One child who died during follow-up was excluded from most analyses because of the incomplete follow-up period with no referrals to CSC services (we cannot conclude that, if we had observed complete follow-up until the age of 6 years, they would not have been referred).

Associated measures of maltreatment

Maternal outcomes

Subsequent pregnancies

All analyses for inpatient and outpatient were based on the 1501 mothers who were in NHS Digital data sources. When additional abortions data were available, these were also included as a subsequent pregnancy, but if there were no NHS Digital data or no abortion data, then these women were assumed as missing. Table 12 shows the rate of subsequent pregnancies since the birth of the BB:0–2 baby, by data source. These vary by source, with the lowest rate found in abortions (taking into account that 2012 data were not available) and the highest among inpatients. Overall, 78% of the cohort of mothers went on to have a subsequent pregnancy. There were no differences in subsequent pregnancy rates split by trial arm overall or by data source (Table 13).

TABLE 12 - Rate of subsequent pregnancies over 6 years since BB:0–2 baby, by data source and across all sources

Data from 2012 are excluded, so the rate of subsequent pregnancy will be underestimated.

Overall n for all inpatient/outpatient data in HES records and where HES data were missing, where abortions data were recorded.

Subsequent pregnancy identified in each data set	Abortionsa	Inpatients	Outpatients	All sources (abortions, inpatients and outpatients)
No, n (%)	1300 (84.9)	40 (27.1)	546 (36.4)	326 (21.6)
Yes, n (%)	232 (15.1)	1094 (72.9)	955 (63.6)	1180 (78.4)
Total (n)	1532	1501	1501	1506b

TABLE 13 - Subsequent pregnancy in the 6 years post BB:0–2 baby, by trial arm

Family Nurse Partnership compared with usual care. Analysis adjusted for stratification (site) and minimisation variables (gestational age, smoking status at recruitment and first or preferred language).

Outcome	FNP arm	Usual-care arm	Adjusteda OR (95% CI); p-value	Absolute risk difference (95% CI)
All sources
No, n (%)	163 (21.7)	163 (21.7)
Yes, n (%)	590 (78.4)	590 (78.4)	1.00 (0.79 to 1.28); 0.984	0.0 (–4.2 to 4.2)
Total (n)	753	753
Inpatients
No, n (%)	207 (27.5)	200 (26.7)
Yes, n (%)	545 (72.5)	549 (73.3)	–	–0.8 (–5.3 to 3.7)
Total (n)	752	749
Outpatients
No, n (%)	280 (37.2)	266 (35.5)
Yes, n (%)	472 (62.8)	483 (64.5)	–	–1.7 (–6.6 to 3.1)
Total (n)	752	749
Abortions
No, n (%)	653 (85.4)	647 (84.4)
Yes, n (%)	112 (14.6)	120 (15.7)	–	–1.1 (–4.7 to 2.5)
Total (n)	767	765

When registerable births were examined (using only admission data as a source), just over two-thirds of the cohort had at least one birth during the 6 years’ follow-up, with no difference between arms (Table 14). The number of births was also similar between arms, with no difference in the interbirth interval and no difference in time to subsequent birth (Figure 6).

TABLE 14 - Time to subsequent registerable birth, by trial arm

HR, hazard ratio; SD, standard deviation.

Family Nurse Partnership compared with usual care. Analysis adjusted for stratification (site) and minimisation variables (gestational age, smoking status at recruitment and first or preferred language).

	FNP arm (N = 752)	Usual-care arm (N = 749)	Adjusteda OR (95% CI); p-value	Absolute risk difference (95% CI)
No subsequent birth, n (%)	276 (36.7)	266 (35.5)
Subsequent birth, n (%)	476 (63.3)	483 (64.5)	0.95 (0.77 to 1.18); 0.662	–1.2 (–6.0 to 3.7)
Of these, the number of births per mother over the 6-year follow-up period
1	326 (68.5)	331 (68.5)
2	124 (26.1)	121 (25.1)
≥ 3	26 (5.5)	31 (6.4)
Number of subsequent births, n (%)			Adjusteda IRR (95% CI); p-value
No birth	276 (36.7)	266 (35.5)	Reference
1	326 (43.3)	331 (44.2)	0.95 (0.76 to 1.19); 0.655
2	124 (16.5)	121 (16.2)	0.99 (0.73 to 1.34); 0.955
≥ 3	26 (3.5)	31 (4.1)	0.80 (0.46 to 1.39); 0.435
Interbirth interval between first and second child (days)			Adjusteda HR (95% CI); p-value
Mean (SD)	476 (1049.5)	483 (1105.1)	0.99 (0.88 to 1.13); 0.938
Median (25th to 75th centiles)	1027 (590 to 1506.75)	1065 (665 to 1538)

FIGURE 6.

Time to subsequent birth (days) by trial arm.

Child health, developmental and educational outcomes

Early-years assessment

Of the 1547 children in the cohort, 1476 (95.4%) were included in the EYFS profile data set, five of whom were marked as absent on the day or missing an assessment. These were excluded from the analysis, leaving 1471 children with an assessment remaining. The proportion of children achieving a GLD (a score of ≥ 2) in all five areas of learning and in all 17 early-learning goals was higher in the FNP arm than in the usual-care arm, with evidence of a significant between-arm difference (Table 16). This pattern was also observed for each of the five areas of learning, although it was not formally tested statistically. When the overall total point score was examined (ranging from 17 = score of 1 across all areas to 51 = score of 3 across all areas), the average scores were similar in each arm (see Table 16). Figure 7 shows the distribution of the total points score over all 17 areas. When the total score was categorised into scores equal to 34, scores < 34, and scores > 34, 34 points was the most common outcome (equivalent to a child achieving the expected level in every learning area), with 25% of children in both the FNP and usual-care arms achieving this score. The FNP arm had a higher proportion of children obtaining a score of > 34 than the usual-care arm.

TABLE 16 - Early-years assessment outcomes by trial arm

SD, standard deviation.

Family Nurse Partnership compared with usual care. Analysis adjusted for stratification (site) and minimisation variables (gestational age, smoking status at recruitment and first or preferred language).

Family Nurse Partnership minus usual care.

Children achieving a GLD are those achieving at least the expected level in the prime and specific areas of learning.

Odds ratio from logistic model.

Total point score ranges from 17 to 51, with a higher score indicating a better level of development.

Mean difference from linear model.

Note

Source: NPD, DfE.

	FNP arm (N = 743), n (%)	Usual-care arm (N = 728), n (%)	Total (N = 1471), n (%)	Adjusteda parameter estimate (95% CI)	p-value	Absolute differenceb (95% CI)
Achieving a GLD
Achieving a GLD in all five areas of learningc	431 (58.0)	380 (52.2)	811 (55.1)	1.26d (1.03 to 1.55)	0.026	5.8 (0.7 to 10.9)
Prime areas
Communication and language	642 (86.4)	613 (84.2)	1255 (85.3)	Not tested, descriptive only	–	2.2 (–1.4 to 5.8)
Physical development	676 (91.0)	643 (88.3)	1319 (89.7)	Not tested, descriptive only	–	2.7 (–0.5 to 5.8)
Personal, social and emotional development	668 (89.9)	634 (87.1)	1302 (88.5)	Not tested, descriptive only	–	2.8 (–0.4 to 6.1)
Specific areas
Literacy	493 (66.4)	458 (62.9)	951 (64.6)	Not tested, descriptive only	–	3.4 (–1.4 to 8.3)
Mathematics	545 (73.4)	516 (70.9)	1061 (72.1)	Not tested, descriptive only	–	2.5 (–2.1 to 7.0)
Achieving a GLD in all 17 early-learning goals	412 (55.5)	365 (50.1)	777 (52.8)	1.24 (1.01 to 1.52)	0.043	5.3 (0.2 to 10.4)
Total point score
Mean (SD)e	32.22 (7.25)	31.59 (7.62)		0.65f (–0.11 to 1.41)	0.094	–
Score of < 34	325 (43.8)	345 (47.4)
Score = 34	187 (25.2)	183 (25.1)
Score of > 34	231 (31.1)	200 (27.5)

FIGURE 7.

Distribution of the total point score over all 17 early-learning goals (range 17–51 points). (a) FNP; and (b) usual care. Source: NPD, DfE.

Treatment efficacy on the early-years assessment total point score

The primary analysis was re-run to investigate the effect of the FNP dosage (number of visits over all delivery phases) using complier-averaged causal effects modelling by fitting a structural mean model. Adjusting the analysis for receipt of FNP, we observe a 0.02 increase in point score in the between-arm mean difference in early-years total score (as the number of visits increase, so does the score); however, the CI around this estimate is wide (–0.004 to 0.040). The maximum number of visits over the whole period of the FNP is 64 (14 in the pregnancy phase, 28 in the infancy phase and 22 in the toddlerhood phase). The estimated treatment efficacy for participants receiving all 64 visits was 1.15 (95% CI –0.26 to 2.56; p = 0.106), showing no change to the overall conclusions, compared with the primary analysis.

Subgroup analyses on the early-years assessment total point score

Of the five prespecified subgroup analyses, the only subgroup that appeared to have a differential intervention effect was mothers aged < 16 years at recruitment, for which a 3.5-score difference was observed between arms (Figure 8) (see Appendix 7, Table 44).

FIGURE 8.

Forest plot of estimates from the subgroups for EYFS profile score. Vertical solid line represents no effect (mean difference = 0) vertical dashed line indicates the overall treatment effect for EYFS total score (adjusted mean difference = 0.65). EET, employment, education or training. Source: NPD, DfE.

Additional adjustment for month of birth

What is observed from the writing assessment is the increase in the rates of children reaching at least the expected standard between the two academic years (overall, from 45.7% in 2016/17 to 66.5% in 2017/18). This is reflective of all assessments across the 2 academic years in each arm (Table 19). This is mainly explained by the distribution of births for the children for each academic year. Reflecting the recruitment period of the trial, children with KS1 results available in the academic year 2016/17 were born between October 2009 and August 2010, but the distribution of month of birth was skewed towards the summer months (42% were born between June and August 2010), whereas children appearing on the 2017/18 academic year were born between September 2010 and February 2011 (Figure 9).

TABLE 19 - Proportion of children reaching the expected standard in KS1 assessments by trial arm and academic year

Note

Source: NPD, DfE.

KS1 assessment	Trial arm	Academic year (%)
		2016/17	2017/18
Reading	FNP	60.6	74.8
	Usual care	54.0	73.5
Mathematics	FNP	56.2	74.0
	Usual care	54.0	75.9
Science	FNP	68.5	81.0
	Usual care	63.7	82.9

FIGURE 9.

Distribution of children’s month of birth by trial arm. Source: NPD, DfE

There is a nationally shown relationship between rates of children reaching the expected standard and month of birth, for example a 17% difference in reading level for children born in August and September. 70 Therefore, the 2017/18 cohort of children do not represent the whole academic year, but are biased towards those who are more likely to achieve the expected standard. This indicates that the rate of children reaching the expected standard varies by their month of birth, which is important as a moderator of programme effect. As a sensitivity analysis, the main analyses were adjusted for a child’s month of birth (categorised into quarter of birth); evidence of a between-arm difference was found in reading assessments (Table 20). In addition, the early-years assessments were also adjusted for a child’s month of birth (see Table 20), which strengthened the association found in Table 16.

TABLE 20 - Comparison of parameter estimates before and after adjustment for child’s montha of birth

Quarter of birth runs from September to November, December to February, March to May and June to August.

Odds ratio represents the FNP arm compared with the usual-care arm.

Gestational age, smoking status at recruitment, and first or preferred language.

Children achieving a GLD were those achieving at least the expected level in the prime and specific areas of learning.

Note

Source: NPD, DfE.

KS1 outcome	ORb (95% CI); p-value
	Adjusted for site and minimisation variablesc	Adjusted for site, minimisation variablesc and month of birth
Reading level
Reaching at least the expected standard	1.23 (0.99 to 1.53); 0.051	1.26 (1.02 to 1.57); 0.035
Expected standard	1.24 (0.99 to 1.56); 0.056	1.27 (1.01 to 1.59); 0.042
Higher standard	1.20 (0.88 to 1.65); 0.250	1.26 (0.91 to 1.75); 0.161
Mathematics level
Reaching at least the expected standard	1.04 (0.84 to 1.28); 0.731	1.06 (0.85 to 1.31); 0.613
Expected standard	1.06 (0.85 to 1.32); 0.611	1.07 (0.86 to 1.34); 0.527
Higher standard	0.93 (0.64 to 1.35); 0.711	0.93 (0.74 to 1.17); 0.522
Science level
Reaching at least the expected standard	1.14 (0.91 to 1.43); 0.254	1.16 (0.92 to 1.47); 0.197
Writing level, academic year 2017/18
Reaching at least the expected standard	1.24 (0.97 to 1.60); 0.090	1.26 (0.98 to 1.62); 0.076
Expected standard	1.29 (1.00 to 1.68); 0.054	1.30 (1.00 to 1.69); 0.050
Higher standard	0.92 (0.51 to 1.64); 0.769	0.97 (0.54 to 1.75); 0.917
Early-years assessment
Achieving a GLD in all five areas of learningd	1.26 (1.03 to 1.55); 0.026	1.31 (1.05 to 1.62); 0.015
Achieving a GLD in all 17 early-learning goals	1.24 (1.01 to 1.52); 0.043	1.27 (1.03 to 1.58); 0.027
Total point score	0.65 (–0.11 to 1.41); 0.094	0.70 (–0.03 to 1.42); 0.060

Treatment efficacy on Key Stage 1 attainment

After adjusting for month of birth, we further explored treatment efficacy. Adjusting the analysis for FNP receipt, we observed an increase in the odds of an event occurring in the FNP arm, compared with the usual care arm, for every unit increase in FNP visits received. For all areas of learning (reading, writing, mathematics and science), adjusting the analysis for FNP receipt strengthens the effect of FNP. However, it is the reading and writing assessments for which, when the full dosage of 64 FNP visits is received, the odds reach statistical significance. For reading assessments, the odds of reaching the expected standard increase from 1.23 (95% CI 0.99 to 1.53; p = 0.051) in the main analysis to 1.38 (95% CI 1.07 to 1.77; p = 0.015). The efficacies per visit were as follows: reading, 1.005 (95% CI 1.001 to 1.009; p = 0.015); mathematics, 1.001 (95% CI 0.997 to 1.005; p = 0.535); science, 1.004 (95% CI 0.999 to 1.008; p = 0.112); and writing, 1.013 (95% CI 1.09 to 1.017; p = 0.001).

Subgroup analyses on Key Stage 1 attainment

The prespecified subgroup analyses (i.e. maternal age, NEET status, IMD quintile, adaptive functioning, and sex of child) are detailed in Appendix 8, Tables 46 and 47, for reading, mathematics and science and in Appendix 8, Table 48, for writing. They are also shown in Figures 10–13. There were no significant differences in the effect of the FNP between boys and girls [denoted by the p-value for comparison between two treatment effects (interaction only)], although the differences between boys and girls in the proportion of children reaching the expected level are large (and drive the significance of the overall interaction, including main effects). Effect differences for sex are seen for the writing assessment (which uses only data from academic year 2016/17). When examining how the intervention effects in each KS1 assessment differed for mothers aged < 16 years at recruitment, compared with mothers aged ≥ 16 years, differences were observed in mathematics and writing, with a larger effect seen in mothers aged < 16 years than for mothers aged ≥ 16 years at recruitment. None of these conclusions changed after adjusting for month of birth (post hoc analysis).

FIGURE 10.

Forest plot of estimates from the subgroups for reading. The vertical solid line represents no effect (OR 1), and the vertical dashed line indicates the overall treatment effect for the percentage reaching at least the expected standard in reading (aOR 1.26). EET, employment, education or training. Source: NPD, DfE.

FIGURE 11.

Forest plot of estimates from the subgroups for mathematics. The vertical solid line represents no effect (OR 1), and the vertical dashed line indicates the overall treatment effect for the percentage reaching at least the expected standard in mathematics (aOR 1.06). EET, employment, education or training. Source: NPD, DfE.

FIGURE 12.

Forest plot of estimates from the subgroups for science. The vertical solid line represents no effect (OR 1), and the vertical dashed line indicates the overall treatment effect for the percentage reaching at least the expected standard in science (aOR 1.16). EET, employment, education or training. Source: NPD, DfE.

FIGURE 13.

Forest plot of estimates from the subgroups for writing. The vertical solid line represents no effect (OR 1), and the vertical dashed line indicates the overall treatment effect for the percentage reaching at least the expected standard in writing (aOR 1.26). EET, employment, education or training. Source: NPD, DfE.

Analysis of health-care resource use and costs

The mean secondary health-care resource use for each participant (mother and child separately) between 2 and 6 years of follow-up is shown in Table 21. For both health-care resource use and associated costs, negligible incremental differences were observed across each resource type for both mothers and children. Resource use was generally slightly lower in the usual care arm than in the FNP arm across most categories, as detailed in Table 21.

Conversely, although small, the cost differences tended to be slightly lower for the FNP arm than for the usual-care arm. As resource data were costed individually, it is possible for costs to vary depending on what visits entailed (i.e. more complicated visits will incur a greater cost than less complicated visits of the same duration). Therefore, it is possible for one arm to have less, or equal, resource use than the other arm, but still incur a greater cost. This approach enables presentation of actual resource use and costs, based on recorded routine data for individual participants.

For mothers, the greatest mean resource use over the BB:2–6 study period was seen for outpatient attendances [23.29 (95% CI 21.83 to 24.75) for the FNP arm vs. 22.61 (95% CI 21.25 to 23.97) for the usual-care arm, mean difference 0.68; p = 0.356]. This was followed by A&E attendances [5.19 (95% CI 4.47 to 5.91) for the FNP arm vs. 4.93 (95% CI 4.42 to 5.44) for the usual-care arm, mean difference 0.26; p = 0.515], overnight admissions [3.04 (95% CI 2.83 to 3.25) for the FNP arm vs. 2.99 (95% CI 1.19 to 4.79) for the usual-care arm, mean difference 0.05; p = 0.500] and day admissions [2.93 (95% CI 2.68 to 3.18) for the FNP arm vs. 2.91 (95% CI 2.62 to 3.20) for the usual-care arm, mean difference 0.02; p = 0.589]. Similarly, for children, the greatest resource use was observed for outpatient attendances [6.89 (95% CI 6.02 to 7.76) for the FNP arm vs. 7.44 (95% CI 6.26 to 8.62) for the usual-care arm, mean difference –0.55; p = 0.821], followed by A&E visits [4.93 (95% CI 4.56 to 5.30) for the FNP arm vs. 4.62 (4.29 to 4.95) for the usual-care arm, mean difference 0.31; p = 0.292], overnight admissions (all cases) [1.57 (95% CI 1.43 to 1.71) for the FNP arm vs. 1.55 (95% CI 1.40 to 1.70) for the usual-care arm, mean difference 0.02; p = 0.882] and day admissions (all cases) [0.98 (95% CI 0.78 to 1.18) for the FNP arm vs. 0.97 (95% CI 0.76 to 1.18) for the usual-care arm, mean difference 0.01; p = 0.883].

Resource use and costs associated with the FNP arm, compared with the usual-care arm, are reported in the cost–consequences balance sheet (see Tables 22 and 23) for both mothers and children. For children, these were also stratified as all attendances, all attendances excluding injuries and ingestions, and injury and ingestion attendances only. Secondary care costs for all attendances were generally slightly lower for the FNP group than for the usual-care group. Overnight inpatient stays for both mother [£2827 (95% CI £2709 to £2944.19) for the FNP arm vs. £2845 (95% CI £2735 to £2954) for the usual-care arm, mean difference –£17.79; p = 0.521] and child [£1963 (95% CI £1669 to £2257) for the FNP arm vs. £2034 (95% CI £1638 to £2429) for the usual-care arm, mean difference –£70.76; p = 0.586] were the main drivers of costs; both were lower in the FNP arm than in the usual-care arm, but, again, the differences were negligible. The incremental differences in costs were small for mother and child over the BB:2–6 study period, but the FNP arm generally incurred slightly lower costs than the usual-care arm. The greatest incremental difference observed for mothers was in outpatient attendances (£55.30; p = 0.398), and favoured usual care over FNP. For children, the highest resource costs were associated with overnight admissions, followed by day admissions [£744.94 (95% CI £539.06 to £950.82) for the FNP arm vs. £724.90 (95% CI £550.38 to £899.42) for the usual-care arm, mean difference £20.04; p = 0.804], outpatient attendances [£673.24 (95% CI £586.49 to £759.99) for the FNP arm vs. £727.79 (95% CI £605.94 to £814.54) for the usual-care arm, mean difference –£54.55; p = 0.838], and A&E visits [£395.73 (95% CI £365.51 to £425.95) for the FNP arm vs. £366.83 (95% CI £340.45 to £393.21) for the usual-care arm, mean difference £28.90; p = 0.208].

When compared with the cost–consequences balance sheet from the BB:0–2 trial32 (costs are shown in Appendix 10), a similar pattern emerges for both studies, that is lower costs for inpatient stays and higher costs for outpatient attendances for FNP participants than for usual-care participants. However, unlike the BB:0–2 trial, the BB:2–6 study found higher A&E costs for FNP participants. Similar to the BB:0–2 trial, inpatient stays were the biggest driver of costs among mothers, but, unlike the BB:0–2 trial, they were not the greatest driver of cost difference; this was observed in outpatient attendances, and favoured the FNP over usual care. For children, however, inpatient stays were the biggest driver of both cost and incremental cost difference.

Sensitivity analysis

Each health-care resource analysed was coded and costed using the NHS Digital Reference Cost grouper,71 with each episode costed as it would have cost the NHS. This approach is more detailed and comprehensive than applying an average resource unit cost to each resource unit consumed and gives a more accurate picture of costs. 72 As costs were assigned based on the year that the resource use was consumed, it was possible that costs could be affected by inflation; therefore, sensitivity analyses were undertaken using different discount rates (1.5% and 3.5%). Using a discount rate of 1.5% instead of 3.5% showed no real difference in costs between FNP and usual care.

Analysis of costs and consequences

The CCA shows that there are no significant differences between the FNP and usual-care groups with respect to the primary study outcome of CIN status (OR 0.98, 95% CI 0.74 to 1.31; p = 0.902), balanced with little difference in secondary health-care costs over the medium term. In general, with respect to the secondary study outcomes (1) objective measures of maltreatment; (2) associated measures of maltreatment; and (3) child health, developmental and educational outcomes, no significant differences were observed between the trial arms, other than in the early-years assessment, for which, for both achieving a GLD in all five areas of learning (p = 0.026) and achieving a GLD in all 17 early-learning goals (p = 0.043), the results favoured FNP over usual care.

Summary

In summary, the BB:2–6 study shows minor differences in resource use and costs between the FNP and usual-care groups, for mother and child, over the BB:2–6 study follow-up period. This is mirrored in the consequences, for which analysis showed no benefit in the primary outcome, and with significant differences, favouring FNP, observed in only two of the secondary outcomes.

Aim

The aim of the public involvement activities was to involve and value lay input to optimise the quality of the research and its impact on policy and practice. We applied this aim to three main aspects of the study: data-linkage methods, study outcomes and dissemination of study findings. To meet the overall aim, the public involvement activity in the study had the following objectives:

1. To optimise the acceptability of the proposed models for dissent and data linkage in the BB:2–6 study to the study cohort.

2. To understand the acceptability of data linkage to members of the public. Acceptability here relates to the kinds of participant-level data collected, for example hospital attendance, child maltreatment, the linking of self-report and routine data, and how issues of consent or dissent are dealt with.

3. To ensure that communication with research participants explains issues relating to data linkage in a clear manner, including points relating to how their data are used, the security and de-identification processes employed, and participants’ rights in relation to consent/dissent.

4. To seek the views of members of the public on the importance of the study outcomes being measured and how best to present them in dissemination activities.

5. To consult on how to communicate the study’s findings to research participants (selection of dissemination methods, formatting of results presentation).

6. To assess how the public involvement methods used impact the quality and conduct of the research.

Thus, objectives 1–3 concerned data linkage, whereas objective 4 was related to the presentation of study outcomes, and which (if any) might be prioritised for inclusion in dissemination materials. Objective 5 covered the communication of study findings to participants, and objective 6 assessed the impact of the public involvement work and the extent to which we achieved our aim and objectives. Methods for and outcomes from work relating to objectives 1–5 are presented in this chapter. Objective 6 is addressed in Chapter 8, where we assess the extent to which the public involvement work addressed the aim and objectives.

Methods

Results

Animation development

Based on insights from the initial meeting with Our Place and drawing on our own reflections of communicating data linkage to the study cohort, key topics and messages for the animation were identified. Fiona Lugg-Widger prepared a draft script for the animation, which was discussed by the SMG. In the session with ALPHA, the group was split into pairs. Each pair was asked to read through the draft script and to suggest images that could be used to illustrate key points. During feedback from each pair, we were able to produce some potential visuals (Figures 14 and 15), and we also sought feedback from participants on any parts of the script that they felt were unclear or could be improved.

FIGURE 14.

Draft visuals from the ALPHA group session.

FIGURE 15.

The ALPHA group discussing the visuals for the animation.

Our Place

Seven mothers and their children attended the group on the day. Four participated in the session. The group was given a copy of the data-linkage script (which included the voice-over element only) and told that an animation was being developed that would clearly explain a research method we use, called ‘data linkage’. To test the current script, no further information was provided, as the animation itself needed to convey all the information. The voice-over element of the animation was read to the group and they were asked to identify any areas that were not clear, and to also provide suggestions on images/graphics that could accompany the voice-over.

Suggestions were made on minor changes to the script, but no major revisions were recommended and the group felt that, overall, it was easy to understand and follow. The group offered a number of ideas on possible dissemination channels for the film. As well as key social media sites [e.g. YouTube (YouTube, LLC, San Bruno, CA, USA)] and sites such as Mumsnet [www.mumsnet.com/ (accessed 29 September 2020)], they also suggested showing the animation in GP surgeries. It was noted, however, that GP surgeries often displayed films/animations without any volume, so our animation would not work in this context if it relied on a voice-over. Finally, the participants shared their thoughts on how to optimise public engagement with the animation. The group members were asked if they would be likely to click on (access) the animation if they came across it by chance. They said they would not be likely to click on the animation, and that, in general, they were unlikely to click on a link unless it was something that was clearly of relevance to them, a form of entertainment, or a site that had been recommended to them by someone they trusted. The group also made several suggestions concerning the kind of voice they would like to hear during the animation. There was a general preference for a voice that was conversational (i.e. friendly and not too formal in tone) and someone that they could relate to, and who was not too authoritative. The animation can be viewed at www.youtube.com/watch?v=4Ivio5XFgik (accessed 6 October 2020).

Value and presentation of study outcomes (objective 4)

Sessions held with the ALPHA group and Our Place focused on two broad issues: first, the meaning and clarity of key terms (particularly relating to outcomes), and, second, participants’ perspectives on the relative importance of the study’s secondary outcomes, and which of these might be prioritised for inclusion in dissemination.

Maltreatment

When asked to provide a definition of maltreatment (prior to being given the study’s definition), Our Place members put forward a number of suggestions. Most of these definitions were in line with that being employed by the study. Although some alternative terms were suggested by group members (e.g. ‘ill-treated’), there was no consensus on what these might be. The group could not identify a term that might be better than ‘maltreatment’, and noted that some of the potential alternatives (e.g. ill treatment) implied intent, which did not encompass neglect (which was included in our definition of maltreatment). The study definition of maltreatment included acts of omission (neglect) and commission (abuse), but did not define these or distinguish between them in terms of intention. However, group members perceived that some forms of neglect could be unintentional, contrasting with abuse, which was an inherently intentional behaviour.

Discussion with members of ALPHA focused on how the study should manage the sensitive nature of words such as maltreatment and mistreatment when presenting study results to research participants and members of the public. ALPHA members felt that the need to identify levels of maltreatment and other negative associated factors relating to a CIN status was important. However, they felt that, rather than say the study is looking at levels of maltreatment, it might state that it is looking into the quality of life or the development of the child. This was put forward as a way of managing the sensitive nature of maltreatment and of limiting its potential negative connotations.

Child in need

In the session held with ALPHA, members were asked to describe how they understood the term CIN. Their initial thoughts were related to their experience of the British Broadcasting Corporation (BBC) Children in Need charity night and its aims of improving the lives of children from around the world.

Having offered examples of what they thought might constitute a CIN, ALPHA members were provided with the legal definition (which was used by the study). ALPHA members compared their initial thoughts with the study definition to see if this needed to be reframed for members of the general public to understand. ALPHA members suggested that the definition of CIN status being used by the study was quite explanatory and that there was no need to include more information. However, they did suggest that it may be worthwhile to include a link to a CIN website or some more information that people would be able to access. They also suggested that it was important to mention that this study intervention would be addressing UK-based children in need.

In the Our Place session, participants’ initial definitions of the term CIN were also broadly aligned with the definition employed by the study. They felt that this term was clear and self-explanatory; they also felt that there was the possibility that members of the public might associate it with high-profile charity projects (e.g. BBC’s Children in Need), but that this was, to some extent, impossible to avoid.

Secondary outcomes

Each ALPHA member was asked to take one or two outcomes and consider their clarity of meaning (i.e. if more information was required to allow full understanding) and acceptability of phrasing. They were asked to do this without prior explanation from the researchers as to the rationale for the inclusion of outcomes, their exact meaning or how they would be interpreted (i.e. in which direction a favourable difference between intervention and control groups would be). For example, for length of time in care, we did not elaborate on whether or not we were assessing whether the FNP reduced or increased this. This approach was designed to help us understand how members of the public might interpret dissemination materials (whereby written/online information would need to be self-explanatory) and enable us to understand ALPHA members’ initial perceptions of what we were trying to measure and why. Each member discussed their outcomes with the group; this encouraged further feedback from those present.

Following this, the group was asked to discuss the relative importance of each outcome and to rank them accordingly (from least to most important). This was through informal discussion, rather than scoring each outcome. Appendix 11, Table 57, shows the agreed ranking and queries or suggestions regarding the presentation of each outcome.

For the session with Our Place, we knew that there might be greater limits on the amount of time we could work continuously with participants (e.g. because they were looking after young children); therefore, we modified the ranking exercise to take the form of two shorter activities. First, we asked participants to undertake a ranking exercise for the secondary outcomes relating specifically to maltreatment, and then repeated the same exercise for the remaining outcomes. As for the ALPHA members, we also asked participants to identify and discuss the meaning of each outcome and any that were unclear or problematic.

For maltreatment-related outcomes, Our Place participants ranked ‘injuries and ingestions’ and ‘Reasons why children are identified as being children in need’ as the two (joint) most important outcomes. The group suggested specifying the severity of the injury (i.e. major or minor). There was also concern regarding the reason for the injury. For example, a broken arm due to a ‘normal childhood accident’ (e.g. falling off their bike) would have a different meaning to ‘wilful’ abuse/neglect/ignorance. In relation to the second outcome (reasons why children are identified as being children in need), it was felt that ‘purposeful/wilful’ abuse or neglect was more important information to know, as this was very different from instances in which a child was disabled, or when a new mother might need extra support because of lack of knowledge.

Figure 16 and Appendix 11, Table 58, show the Our Place members’ ranking of the secondary outcomes relating to maltreatment, and their comments on each of the outcomes. Several outcomes were regarded as being of equal importance. Appendix 11, Table 59, shows the remaining outcomes and how they were ranked.

FIGURE 16.

Group activity to rank outcomes with Our Place members.

As can be seen, for some outcomes, the two groups (ALPHA and Our Place) were very similar in their rankings. For instance, ‘injuries and ingestions’ was given high importance by both groups. In other cases (even allowing for the slightly different methods used to rank the outcomes in the two groups), there were areas of divergence, such as the ranking of ‘cause of death’, which ALPHA placed greater emphasis on.

Both groups made similar points concerning the need to provide more specificity or detail on the meaning of certain outcomes. In ranking the secondary outcomes in terms of importance, Our Place participants reflected on the fact that how they ranked them was based, in part, on their own context (e.g. the age of their children) and that other members of the public reading the study findings may also identify what was important to know on this basis. For example, outcomes related to educational attainment might be more relevant (and, therefore, of more importance) to parents who had school-age children.

Our Place members made two other key points about the presentation and selection of outcomes. First, that each outcome should ideally be presented as a single concept, as this would make reading and comprehension easier. This applied to outcomes such as ‘injuries and ingestions’, for instance. Second, especially given the breadth of outcomes measured, they felt that it was important for the research team to make clear why they had chosen the selected outcomes. Thus, to some extent, they felt that the presentation of a clear rationale for why outcomes had been measured was as important as the ranking of the outcomes.

Dissemination methods (objective 5)

Written invitations to FNP graduates sent on our behalf by FNP teams inviting recipients to group-based discussions was one of the main recruitment strategies, but did not prove effective. We therefore revised the approach by asking FNP teams to identify clients/graduates with whom they could make face-to-face contact (e.g. by mentioning the study during routine home visits). The revised recruitment materials (and requests for FNP teams to help us) offered individuals a number of possible formats for meeting with us (e.g. one to one with a researcher, jointly with a friend/family members) and flexibility over timing and location (and not an invitation to a pre-planned group discussion on a specific date). At the time of writing (October 2020), one such meeting has now been held with a FNP graduate. Although this approach may not offer all of the advantages of a structured group discussion, it is hoped that it may increase levels of interest and engagement.

As outlined earlier, this work will focus on (1) the best methods to use for dissemination to research participants and members of the public (e.g. paper-based, websites, social media) and (2) how to format the presentation of results for the outcomes that are included in these dissemination materials. For instance, this might include text summaries, visualisations of key findings and various forms of graphs/bars/charts. Feedback from the FNP graduate who we have worked with has helped us to identify presentation formats that might be easier to navigate (e.g. bar charts rather than pie charts), and the potential value of written dissemination materials (if the reader is interrupted, written materials may be easier to pick up and re-engage with than some online media). We were also able to explore the prioritisation of outcomes for the dissemination activities. The discussion highlighted the potential importance of outcomes with immediate impacts on family well-being, in addition to the hypothesised long-term effects, for example prevention of child maltreatment. There were similarities between the key points made here and those that were highlighted during the work we did with Our Place members, and these merit further exploration with FNP graduates.

The work that we have completed (particularly with Our Place and ALPHA) has already helped us to develop key aspects of the approach to dissemination. For example, the groups we have worked with have helped us identify how complex aspects of the study (e.g. data-linkage methods) can be communicated in an accessible and clear manner through visualisations, and we will apply this learning to the framing of the key results. We have also strengthened our understanding of how to frame study outcomes in ways that make them more readily understandable by making the rationale for their inclusion explicit and presenting them as single concepts whenever possible. For example, in relation to children in care, Our Place members suggested separating ‘length of time in care’ and ‘legal status’ (we had presented them on a single card when we asked Our Place members to rank outcomes). More generally, we have developed our capacity to present key aspects of the study (rationale, methods, outcomes) to members of the public in a clear and accessible way, and this will feed directly into our approach to dissemination.

Discussion and conclusions

Public involvement has been important at many stages throughout the project. Involving the public has enabled us to bring new perspectives to our thinking and to reflect critically on the design and presentation of the research. We summarise the key contributions that the public involvement work has made to the quality and conduct of the study, mapped against the objectives that we set ourselves.

Reflections/critical perspective

The importance of public involvement in research is now widely recognised. Recent methodological guidance, including the publication of national standards74 for public involvement by the Public Involvement Standards Development Partnership (a collaboration of national agencies and funders, including NIHR), has been designed to help research teams develop practices that will support and promote effective public involvement. The design of our public involvement activities did not draw on these standards (which were not published at the time), but they have informed our reflection on the successes, limitations and challenges of our public involvement work. The public involvement work that we have undertaken is strongly aligned with some of the key principles and actions recommended by the standards. 74 For example, we have sought to address barriers to involvement (a key focus of standard 174) and to build the skills and confidence of the members of the public that we have worked with (standard 374).

A key strength of our public involvement work is that we have sought to engage with multiple experiences and voices, including FNP graduates, other young mothers and young people from different backgrounds, for example those with experience of being looked after. By engaging with members of the public, both through group-based meetings and through our plans for one-to-one consultation, we have sought to ensure that adequate time has been provided for our discussions with the public, rather than limiting this to inclusion of a public representative in our SMG meetings. Whenever possible, we have met with members of the public in their own communities and provided as many options as possible regarding where and how they would like to meet. At each stage of our public involvement activities, we have sought to use accessible concepts and language, and to consider the skills and training needs of researchers and members of the public. Input from a specialist public involvement officer (Peter Gee) and regular team discussion after key activities has helped us to develop our skills in engaging with members of the public. Advice from Peter Gee and contacts in the organisations we have worked with has also been important in understanding what background information members of the public might need at the start of public involvement sessions, and how best to support those who might not be used to contributing to a group discussion. In terms of governance, public involvement has been a standing agenda item at our SMG meetings, which has helped embed it in the study and ensure that key insights have been shared with the broader research team. This approach is strongly aligned with the national standards for public involvement (standard 6),74 which emphasise the need for public involvement to be visible and accountable in research management structures and governance.

The work to develop an animation that explains key aspects of data linkage in research studies stemmed directly from the ideas generated by members of Our Place. We have subsequently worked with members of the group (and those in ALPHA) during its development, and sought input on content (e.g. the draft script), appearance (images, colours) and presentation (e.g. style of voice-over, appropriate length of the animation). In the field of public health, co-production of new interventions with members of the target population who will receive them has a number of important benefits, including optimising relevance, acceptability and credibility. 75 We have built co-production into the development of the animation, with the aim of realising these benefits.

During the public involvement work, a number of challenges were encountered. First, the session held with CASCADE Voices was run by a facilitator independent of the research team. Although this had many strengths as a way of working, it did mean that we were not able to discuss directly with the group which areas of feedback we were able to address, and those aspects of the study that, for various reasons, could not be modified. Although we provided information to the facilitator prior to the session concerning the reasons why we planned to contact withdrawn participants, it was not possible for us to pre-empt and therefore provide explanations in advance for all potential questions. Although some of the input from CASCADE Voices members focused on the letter, which we had drafted, some of it was concerned with the broad approach of opt-out versus consent, something we were unable to amend at that time. In subsequent activities with other groups, members of the research team led activities and engagement with participants (Our Place) or did so alongside the existing group facilitator (ALPHA). More direct involvement in the running of the meetings provided us with the opportunity to explain fully which aspects of the study we were seeking input on and to highlight those areas that had either already been finalised or that we were not able to modify. Our experience also suggests that, for a topic as complex as data linkage (and for which provision of some background information will often be needed), it may be helpful to hold more than one meeting with a group. As well as providing more time to focus on specific topics, this also has the advantage of building rapport and shared understanding between researchers and group members, and of providing time for all involved to reflect on learning, (mis)understandings and topics needing further discussion in the period between sessions.

Although we have identified the approach of working with members of the public in their own communities as a strength, this raised several practical challenges. Using mother and baby/toddler meetings (as we did with Our Place) was intended to provide a relaxed and comfortable environment for members of the public to talk with us. But, by virtue of their purpose, they could sometimes be noisy and chaotic environments in which mothers needed to ‘dip in and out’ of participation in discussions, where undertaking head counts of how many people had contributed to an activity was difficult, and where use of audio-recording was impracticable. We sought to address these issues by working with smaller groups of mothers in a separate room, but this was not always possible. These ‘breakout’ sessions were not recorded because of the level of background noise, but, on reflection, we might have sought to record at least part of the discussions, perhaps when we were asking for a summary of people’s thoughts, as this would have provided a more in-depth record. In later meetings with Our Place, we proactively designed activities to have more flexibility (e.g. having some activities that participants could easily join without having to be involved for the whole meeting).

The biggest challenge we faced has been in recruiting FNP graduates, particularly in relation to attending group meetings that we had organised. Whereas meetings with Our Place members took place with an existing group (and at a meeting that they were attending as part of this group), a different approach was required for organising activities with FNP graduates. They were not part of an existing social network or set of meetings that we could access, and they had received FNP on a one-to-one basis. We therefore organised bespoke events to bring FNP graduates together in their local community. The main method of contact was mail-outs that went via FNP staff already known to and trusted by the individuals concerned. We sought to reduce practical barriers to attendance, for example by choosing locations that we thought would be easily accessible by public transport, offering to reimburse travel costs on the day of the meeting and providing a crèche and free refreshments. Significant efforts were made to produce information promoting the events that was accessible and easy to understand. We offered incentives for attendance (lunch, retail vouchers) and also provided alternative ways for people to speak with us if they could not or did not wish to be part of a group discussion. FNP teams provided significant help at various points. They promoted the meetings on our behalf to individuals they thought might be interested, agreed to be present at the start of one of the meetings (so that participants would be greeted by a ‘familiar face’) and also provided feedback on the information we produced. They suggested that the information was approachable and clear and they did not recommend any major changes.

Despite all these efforts, few graduates agreed to take part, and nearly all those who did either cancelled prior to or on the day or did not attend as expected. It is difficult for us to ascertain the reasons why the meetings generated such low levels of interest. Nevertheless, based on our discussions as a research team and input from the FNP teams that helped us, a number of possible explanations have been identified.

Contact was made with FNP graduates via a mail-out that was distributed by FNP teams. We were not able to contact individual graduates directly because of data protection requirements. Therefore, the initial approach was less personalised than it would have otherwise been. FNP teams did not routinely use or update lists of graduates, as they were no longer working with these individuals. Feedback from FNP practitioners was that some contact details were, inevitably, out of date, and that some graduates (possibly a high proportion) may have moved home or even left the area. In Bath, the FNP team advised that, in general, it was extremely difficult to engage parents in group-based activities, and that some group-based meetings organised by local services in the city had ceased to exist partly as a result of this.

The FNP graduates had accessed the service on a one-to-one basis (i.e. one mother meeting with one FNP nurse). We sought to bring together groups of mothers, but, given the individual-level nature of the service, we were not tapping into an existing network or group of linked individuals. This may have made the proposed meetings less appealing, or more daunting for those uncomfortable with group settings, or may simply have meant that our invitation was not as relevant or meaningful to recipients as it might otherwise have been. In Wiltshire, some individuals indicated that they felt uncomfortable about meeting with a researcher whom they did not know. We responded by saying that we would be happy to meet graduates/clients with a family member/friend or FNP nurse present.

Finally, it is possible that, despite our best efforts, some practical barriers to attendance still existed. These may have included the need to use public transport to reach our venues (in Bath we knew that very few participants had access to private transport), work commitments (mentioned by one potential participant) and child-care commitments (e.g. picking up children from school). Despite these challenges, we have achieved the majority of our public involvement objectives. The activities undertaken have optimised the quality of our work and have built our capacity for and skills in undertaking effective public involvement. We are committed to using the valuable insights that this public involvement has generated to help maximise the impact of the study on policy and practice.

In summary, we have worked with different lay groups during the conduct of the study to address several objectives, which broadly relate to optimising study processes, better understanding lay views on the nature of the research and improving how we communicate with the public about it. Existing research and non-research organised groups of young people have added tangible benefits to the study, for example by improving participant-facing materials; by modifying study processes such as dissent registration; and by informing, in detail, an animation explaining routine data and their use in research. We had less success in engaging with individual graduates of the FNP programme, despite considerable thought and effort, and also support from FNP professionals. However, the breadth of input from other lay groups involved may have partially compensated for this. An interesting tension was found when exploring lay participant views on aspects of the study design such as reapproaching women who had withdrawn from the original BB:0–2 trial. Conflicting views arising within and between lay groups is perhaps inevitable in such involvement work, and acknowledging and respecting all perspectives is essential when making subsequent decisions about the study.

Principal findings

Child development

The pattern of early educational attendance up to 4 years was equivalent across study arms. Fewer children in the FNP arm attended privately run day care and more attended local authority day nurseries or ‘other’ service providers than children in the usual-care arm. Rates of school attendance across all available academic years in follow-up were similar across study arms. Children in the FNP arm were more likely to reach a GLD across all five areas of learning by the end of the reception year (58.0%) than children in the usual-care arm (52.2%), and were also more likely to achieve a GLD in all 17 early-learning goals (FNP, 55.5%; usual care, 50.1%). In both cases, the effects were strengthened when adjusting for a child’s month of birth. The small advantage for children in the FNP arm was consistent across all five areas of learning, although we did not test each area of learning separately. In planned subgroup analysis, the beneficial impact of the FNP on total point score was mostly observed for younger (aged < 16 years) rather than older women at study entry, but no other differences by study subgroup were found. Variation in the observed number of visits from a family nurse made no difference to the size of the effect.

At KS1, 65.3% of children in the FNP arm reached the expected standard for reading, compared with 60.5% of children in the usual-care arm (aOR 1.23, 95% CI 0.99 to 1.53). The proportions of children reaching the expected standard for mathematics (FNP, 62.0%; usual care, 61.3%) and science (FNP, 72.6%; usual care, 71.0%) were similar across study arms. There was some difference across study arms for writing (FNP, 48.4%; usual care, 42.9%) when compared using data from the academic year 2016/17. However, none of the group differences for the KS1 outcomes was statistically significant.

As month of birth has a strong relationship with educational attainment in the general school population, we adjusted the main analyses for all KS1 outcomes to take birth month into account. Adjusting for month of birth, children in the FNP arm were more likely to reach the expected level for reading than children in the usual-care arm (aOR 1.26, 95% CI 1.02 to 1.57; p = 0.035). There were no group differences for other KS1 outcomes when making this adjustment.

For children whose families had more visits from a family nurse, the effect for reading was stronger (adjusted difference 1.38, 95% CI 1.07 to 1.77; p = 0.015, if families received all 64 visits). The increased efficacy per visit for writing was also statistically significant (aOR 1.005, 95% CI 1.09 to 1.017; p = 0.001), but there was no effect for either mathematics or science.

Overall, at KS1, sex differences were large, with girls outperforming boys in all four subject areas. The effect between study arms was greater for boys in the FNP arm than for girls, particularly for reading and writing (and strengthened after adjusting for month of birth); for writing, this reached statistical significance. Similarly, although children with younger mothers at recruitment were less likely to reach the expected standard overall, the differences between study arms in favour of children in the FNP arm were greater for younger women, for mathematics and for writing (academic year 2016/17), an effect that reached statistical significance. In addition, for writing (academic year 2016/17), a programme effect was observed for mothers NEET at the time of recruitment; the contrary was seen for mothers in employment, education or training (EET). When tested, no additional interaction effects were found at KS1.

The intervention effects for each of the main outcomes assessed are summarised in Figure 17, and demonstrate the differing pattern of impacts between maltreatment and child developmental outcomes.

FIGURE 17.

Forest plot of estimates from all main outcomes. Vertical solid line represents no effect (OR = 1). a, FNP compared with usual care. Analysis adjusted for stratification (site) and minimisation variables (gestational age, smoking status at recruitment, and first or preferred language). For Early Years and KS1 outcomes, additionally adjusted for month of birth. Source: NPD, DfE.

In an additional exploratory analysis, we developed two cumulative risk scores based on baseline predictors of CIN status and reading attainment at KS1 for children in the usual-care arm. Categorised into low and moderate/high risk, we explored programme subgroup effects, but found no additional benefit of the FNP for children with elevated baseline risk score.

Impact on inequalities

The FNP forms part of a progressive universal approach (i.e. universally accessible services with enhanced access for those requiring special or targeted support) of home visiting to support families at greater risk of adverse outcomes. Young maternal age was selected as a programme criterion, as it is associated with a wide range of adverse outcomes and is a proxy for socioeconomic disadvantage. 18 Although there is considerable complexity involved in potential causal mechanisms, poverty is strongly associated with the risk of a child suffering maltreatment. 76 The intervention, therefore, directly aims to address inequality. The results of the child development outcomes further indicate how the intervention may be especially important for children who may be at additional risk, for example those born to very young mothers, boys and those born in the later months of the school year. The feasibility of tailoring programme delivery (e.g. enrolment criteria, dosage) to intervene where the benefits may be most likely is beyond the scope of this study, but such adaptation is already part of the agenda for the FNP national unit delivering the programme in England. 77 In addition, the programme attempts to reduce inequality by supporting mothers to engage with education and employment, and thereby improve their life course and that of their children. In the current study, we have not been able to fully assess mothers’ economic circumstances because of the particular focus on maltreatment outcomes. The equivalent rates of second pregnancies that we observed provide no indication that the programme has modified one factor that may affect maternal life course. We have previously raised the broader question of how systemic differences between the USA and the UK may interact with the programme to support incremental benefit. 78 We consider that exploring such socioecological influences on programme implementation and outcome remains an important objective.

Interpretation

The FNP programme model aims to promote sensitive and competent parenting as a route to improved child health and development. Nurse-facilitated activities during regular home visits are intended to provide a stimulating and safe home environment, reducing maltreatment and improving language and executive functioning. In this study, we have found minimal evidence of programme impact on children’s likelihood of experiencing maltreatment, but we have found solid evidence of an advantage in early educational attainment.

The strongest evidence for the FNP’s impact on maltreatment comes from the original Elmira trial. 13,79 Olds et al. 13 found reduced substantiated reports of abuse and neglect in the first 15 years of a child’s life, an advantage that emerged only after age 4 years. The Dutch trial of VoorZorg25 similarly found reduced maltreatment reports to child protection services in the Netherlands within the first 3 years of a child’s life among mothers visited by a nurse.

Adapted versions of the NFP in Australia (Family Partnership Programme)80 and in Germany (Pro Kind)29 have also assessed programme impact on maltreatment. Segal et al. 80 reported reduced involvement with child protection and days in care for children in the Family Partnership Programme arm in a trial among indigenous Australian mothers. The German study of Pro Kind is yet to report on its longer-term evaluation, but has followed up children to a similar age as those in our study, using maternal self-report. A 2018 evaluation of the NFP in Pennsylvania, USA, used propensity score matching to compare NFP and control families in rates of use of hospital-based health care for injuries. 81 Although a higher rate of attendance was found among NFP families, these were mostly due to differences in minor injuries; no difference between groups for more serious injuries was observed. Matone et al. 81 point to the need for high-quality implementation to replicate beneficial trial findings. Olds’ original trial9 provides the most rigorous long-term evidence of programme impact when implemented as intended by the developer and when combining data sources to understand maltreatment outcomes. Although some differences were found in our study, for example length of time spent in care for care-experienced children, the numbers involved are small and the over-riding picture is of no overall group difference. The programme was also no more effective in tested subgroups. Although it is still possible that a benefit from the FNP may yet emerge as the children in our cohort get older, we have no evidence currently to suggest that this may be the case. It is also worth recognising differences in the population of clients in receipt of the programme across the different study populations, their social circumstances and how that may determine potential to benefit from the FNP. 78 Similarly, this study has not explored differences in social care systems across countries. Although conditions that may serve to vary the underlying risk of maltreatment, and its likelihood of being detected and then responded to, will differ across countries, our evidence is that the FNP makes no incremental difference in the English setting of our study.

The BB:0–2 trial found maternally reported benefits at age 2 years for children of nurse-visited mothers for both language and developmental outcomes. 22 This new study now provides objective medium-term evidence for programme impact on developmental outcomes at the end of the reception year and at the end of KS1, to build on that picture. The pattern of results shows broad positive impact on school readiness, one that is greatest for children born to the youngest mothers. Although there is overall programme benefit at KS1 when adjusting for birth month, there is also some particular benefit for children born to the youngest mothers (in mathematics and writing), however the small numbers for this group should also be noted.

Similar medium-term programme impact (to age 6 years) on developmental outcomes was reported by Olds et al. 82 in their Memphis trial. These included improvements in attendance at formal out-of-home care, and in intellectual functioning and receptive language scores. In Heckman et al. ’s83 reanalysis of the Memphis trial data, the cognitive benefits of the programme at age 6 years were attributed to both programme-induced improvements in maternal traits and family life investments at age 2 years. Looking forward, Heckman et al. 83 also found that the positive effects persisted through to age 12 years for boys, but not for girls. Although the positive difference found at KS1 for boys in the FNP group across each outcome did not reach statistical significance, it may be possible that the longer-term outlook, particularly for boys in our trial cohort, may be similarly beneficial.

A reduction in maltreatment and an improvement in school readiness and achievement are both predicted benefits of the FNP and are supported by existing US trial evidence. We identified a number of risk factors from the exploratory analyses that could influence both outcomes. These included both common factors (e.g. difficulties with basic skills, young maternal age) and non-common factors (e.g. smoking in pregnancy for children in need only). Further work is required to establish whether the differences in outcomes that we observed reflect theoretically different pathways to effect or, for example, differing contextual factors at operation in the different trial settings in England and the USA. Understanding why the programme may work for some outcomes and not for others in the UK may inform programme optimisation and lead to incremental benefit over usually provided services.

Two factors that we needed to consider further in our main and exploratory analysis, and in interpreting the results, were academic year of assessment and month of birth. School readiness as measured by a GLD in the EYFS has consistently improved in England in the years since children exited the trial at age 2 years. 84 Nationally, in 2014, 60.4% of all children met this threshold; by 2018, the figure was 71.5%. Girls consistently outperform boys, but the sex gap has narrowed during the same period of time (a 16.3-point difference in 2014 and a 13.5-point difference in 2018). In addition to sex, free school meal eligibility, month of birth and presence of SEN also contribute to variation in attainment of a GLD in the EYFS.

Key Stage 1 data are based on teacher assessments undertaken at the end of KS1 (Year 2), when a child is aged 6 or 7 years. Study data were sourced from two school years: 2016/17 and 2017/18. Nationally, girls outperform boys in all subjects, with the largest gap in writing. There are large differences in those reaching expected standards between students eligible for free school meals and by month of birth. In 2017, proportions of children reaching the expected standard increased for all subject areas (by between 1% and 3%), but remained lowest for writing (68%).

The birth dates for children in our study cohort resulted in an uneven spread of children born across calendar months in each year included. Although the individual-level trial randomisation retained a valid group comparison, we needed to further adjust for month of birth to extend generalisability. Doing so revealed the additional benefit the programme could have for those born in the summer months (who traditionally perform worse at KS1). Differences in attainment due to birth month can persist until General Certificate of Secondary Education (GCSE) stage; therefore, it is important to establish whether benefit attributable to the FNP at reception and KS1 is maintained in the long term or fades away. 85,86

In England, the FNP programme remains locally commissioned by a large number of local authorities. Since delivery of the programme to families in the BB:0–2 trial, and partly stimulated by the trial’s findings, the FNP national service unit has led a programme of universal improvements and local changes. These include clinical changes related to specific outcomes and system changes such as reviewing eligibility criteria and modifying visit dosage (both up and down). The subgroup differences that we report here may provide some support for such efforts to target the programme’s delivery. However, our exploratory work looking at benefits for those with multiple baseline risk factors was less informative, based on the data available to us.

Generalisability

The generalisability of the BB:0–2 trial cohort was established previously and found to be broadly representative of the population of women being offered the FNP. 22 With few women dissenting to follow-up in the current study, and with high rates of matching possible via NHS Digital and (for children) the NPD, there was little attrition in the sample up to age 6 years. When the original trial sample and the current study cohort are compared, there are no differences in baseline characteristics and no indication of bias having been introduced by the process of data linkage/dissenting.

The exploratory analysis adjusted for month of birth to determine programme effects when assuming an even distribution of births across the calendar (or academic) year. This was necessary as births to women in the original study were not balanced across months, and there are strong seasonal effects on KS1 scores. Adjusting for season of birth has allowed for a better generalisation of programme effect. Contemporary national data (England and Wales combined) showing month of birth for all women in the period 1995–2014 show a higher rate of births in the months of June to August, with a subsequent dip and then a higher peak of births in September. This is similar to the profile of month of births seen in our study, although there are relatively fewer births in the trial cohort for winter and spring months, compared with the general population. The distribution of months of birth for the study cohort reflects both the month of study recruitment for women and also their gestational age at recruitment. The former will have been driven by the staged opening of sites over a period of months and the total recruitment period (≈13 months). The latter will have been constrained by study eligibility criteria, but will have allowed some variation. However, in both cases, the individual randomisation will have ensured balance across study groups.

As the FNP is a preventative intervention for families at greater risk of adverse outcomes, we would expect families in our study’s usual-care arm to have poorer outcomes than those found in the general population. In comparable years, attainment at a national level was higher than for our usual-care arm for the EYFS profile assessment. In 2015, 66.3% of children achieved a GLD in all five areas of learning, and, in 2016, this rose to 69.3%. 84 This is compared with 52.2% in the study’s usual-care arm. Similarly, in 2015, 64.1% of children achieved the expected level in all 17 early-learning goals, compared with 50.1% in the study’s usual-care arm. At KS1, the pattern of difference is similar. In 2017, 76% of children nationally met at least the expected standard in reading; in 2018, this figure was 75%. 87 This is compared with 60.5% in the study’s usual-care arm.

In social care, the contrast between study participants and the general population of children in England is even more revealing, although published national figures are not summarised in a directly comparable manner to that used in the BB:2–6 study. In 2018, the national rate of children (aged < 18 years) in need at 31 March was 3.4%. 3 Of these, children aged 1–4 years accounted for 17.5% and those aged 5–9 years accounted for a further 24.1%. Although in our study we report a prevalence rate (i.e. of ever being in need up to age 6 years), the rate we found of 21.7% in the usual-care arm shows how vulnerable children in the study are, compared with the national population. In the BB:0–2 trial, we showed how vulnerable study families were based on baseline characteristics, compared with the broader population. In the BB:2–6 study, families not exposed to the intervention have much poorer outcomes than found for the general population. Despite important improvements for developmental benefits for children in the FNP arm, they are still much lower than the population average. Social care outcomes, in particular, remain poor for all families, compared with the broader population in England.

Strengths, weakness and ongoing challenges

The major strengths of the study are the high quality of data linkage achieved via NHS Digital using primarily NHS numbers and, overall, the high level of sample retention. This maintained the representativeness of the original trial and provided a large sample, and hence power, for the analyses. The lack of a similar unique linking field available to the study team for matching to NPD data resulted in a slightly smaller cohort of children available for analysis. Successful efforts to better link health and education identifiers at a national level would have benefits for research, but may also be challenging from a practical and ethics perspective. 88

In this study, we undertook a substantive pilot phase that addressed several objectives. 31 Although it was possible to identify, at the outset, a number of potential study challenges and mitigating strategies, the pilot phase enabled strategies to be optimised and evidenced, in addition to allowing unanticipated challenges to be addressed. The regulatory and governance context of the study, whereby we sought data from multiple providers with varying legal and ethics imperatives, was both complex and dynamic. Our approach had to accommodate multiple providers and be adapted over time (e.g. following the advent of General Data Protection Regulation). 89 The regulatory-compliant model of data linkage we have created has enabled greater understanding of the outcomes for families recruited to the original BB:0–2 trial. This may then inform further follow-up of the same cohort, as well as attempts by other researchers seeking to link data in this environment.

The current study benefits from the random allocation applied in the original trial and the further use of both outcome and descriptive data collected in that study. Although there are approaches that can be used to address the potential bias in observational studies of effectiveness, these were not required here. That, combined with the use of routine data collected wholly independently of the trial, provides substantial reassurance about potential biases. The reuse of trial data in tandem with use of routine service data is also consistent with policy imperatives for efficient study designs. 90,91 Although some costs involved in delivering this study were greater than anticipated for example, because of revisions in costing models used by NHS Digital, the total cost was substantially lower than would have been incurred if data were prospectively collected using maternal self-report.

Nevertheless, a study model reliant on routine data will have placed some limitations on the scope of what is achievable. This will be based both on what data are systematically collected by the services and the quality of data coding at source. For example, the available maltreatment data have provided an essential overview of the key outcomes for our study, but narrative data about individual cases may have added depth to our understanding. The inability to assess resource use, both within the primary care context and from women’s perspective, has placed some limitation on what we can conclude. Similarly, the lack of detailed social care resource data has limited the perspective of the CCA, which therefore primarily focuses on secondary health-care costs. Overall, accessing only routinely available data has enabled us to understand key programme and policy-relevant outcomes.

Using only routine data prescribes the outcomes available for analysis, some of which may lack the measurement properties that research instruments could offer. One such example is the EYFS measure of school readiness, which was a key secondary outcome in our study and which may be less sensitive to change than other instruments. 92 Nevertheless, it does allow ready comparison with both local and national populations. Furthermore, the fact that we were able to demonstrate a programme effect using this measure suggests that the underlying effect is probably even more substantial. Augmenting routine data with standardised research instruments would add value in a future longer-term evaluation.

We selected CIN status as a primary outcome because it was reliably available using routine data and follows a legally defined approach to safeguarding and promoting child welfare. Although its scope is broader than solely maltreatment, abuse and neglect form the majority of reasons why children are identified as in need. This then forms part of our overall assessment of programme impact, which incorporates other related measures such as CPPs, becoming looked after, and injuries and ingestions leading to emergency attendance and admission. We did not exclude as cases those with a primary reason of disability, but, as there were only 12 children in total (FNP, n = 7; usual care, n = 5), doing so would not alter the conclusions.

In the 15-year follow-up of the Elmira trial of the NFP, maternally reported incidents of domestic violence (the term used in the US trial) since birth of the study child were counted, with increased incidence associated with reduction in intervention effect for maltreatment. 93 The intervention itself was not found to alter levels of reported domestic violence, as was also the case in the BB:0–2 trial. Further exploration examined the possible mechanism of this effect and found that, among women experiencing low to moderate levels of domestic violence, programme impact on maltreatment outcomes was mediated through changes in maternal life course (reductions in number of subsequent children and use of public assistance). 94 In the BB:0–2 trial, just over half of all women (n = 607, 54.2%) completed the Composite Abuse Scale measure of intimate partner violence at 24 months (in part because of requirements for scale completion: a face-to-face assessment with no other person present). Small untested trial arm differences showed that non-completers were more likely to be separated at trial baseline, to not be in EET, to have higher deprivation scores based on postcode and to have more difficulties with adaptive functioning. Most completers (n = 362, 60.6%) reported no abuse (score of 0). In the BB:2–6 study, the lack of intervention effect for maltreatment outcomes, the shorter (than the Elmira trial) follow-up period and the availability of maternal-reported intimate partner violence only at 24 months limited our ability to explore any moderator or mediator effects. However, further exploratory work may yet be possible examining programme impact in the context of intimate partner violence.

Our approach to assessing maltreatment used multiple methods and sources of data, all of which were from service records (either social services or health services). This is similar to the method used by David Olds in his original Elmira trial,9 and contrasts with other approaches that have used maternal self-report, for example in the evaluation of the German Pro Kind intervention. 29 Although it has been suggested that surveillance bias is unlikely to be a serious problem when evaluating maltreatment using verified service data (i.e. unlikely to inflate numbers of children being reported when in receipt of home-visiting),25,95 others have found that this could be substantially higher when clients are actively engaged with services;96 therefore, the potential for such bias still needs to be acknowledged.

One other consideration when using routine data is that the method for assessing outcome can change independently of the evaluation. Changes in the 2017/18 Writing Teaching Assessment frameworks meant that the assessments in 2016 and 2017 are not directly comparable. 43 The changes made included a more flexible approach (i.e. greater discretion being applied by teachers to ensure that a particular weakness does not prevent an accurate judgement of overall attainment) and revised ‘pupil can’ statements (e.g. a greater emphasis on composition). This meant that we had to analyse the 2 years of data separately (and the later year only descriptively because of reduced numbers), although the trial’s individual randomisation still allowed for a valid comparison in both cases.

It is now standard practice to have active public involvement in clinical trials, but a less well-established practice in routine data studies. We considered that it was important to have strong involvement in this study because of the dissent model of linkage being used and the relative unfamiliarity among the general public of the use of routine data for research. 97 We extended a model of involvement used in our BB trial to include multiple lay stakeholder groups engaged at different touch points in the study (in part, this was led by requirements placed on us by the CAG review panel). The role of public stakeholders was synchronous with the study life cycle (e.g. from initial approvals through to dissemination) and helped shape different processes and materials, including the development of animations explaining what routine data are and how they are used in research. These will have benefits beyond the current study for researchers and members of the public alike. One group that we did have difficulty effectively engaging with were FNP graduates, despite substantial support from local FNP teams. It is possible, therefore, that unique perspectives of programme clients were not well represented in our planning, although the three other young people groups we did engage with are likely to have compensated for that to some extent.

We planned that all children would be followed up to KS1, representing the latest follow-up point for all children in the study. In practice, the annual release schedule of data from the NPD and the range of study children’s birth dates meant that the youngest children were not initially included in the main analysis for this outcome. We agreed with both the funder and the SSC that the remaining data should be added to enable a full data set, despite then delaying submission of the final report. By repeating the KS1 analysis on the now full data set, we identified discrepancies in rates of children reaching the expected standard, compared with the analysed partial data set. This informed additional post hoc analyses, which clarified the importance of month of birth (analysed by year quarter) as a moderator of programme effect. Adding month of birth was consistent with the original statistical analysis plan (i.e. as an additional subgroup) and has importantly augmented the final results, allowing a much more nuanced understanding of factors influencing educational outcome and how that interacts with the FNP.

A CCA provides a descriptive summary of the costs for decision-makers across a range of sectors. 63 It can examine whether or not investing resources earlier in the life course can generate benefits and potentially reduce costs over the longer term. 98 A CCA can capture a broad range of outcomes, not restricted to health outcomes, which may be especially meaningful for complex interventions generating multiple effects. It is also a pragmatic solution when health economic analyses such as a cost–utility or cost-effectiveness analysis is unfeasible. However, it is constrained by not providing definitive conclusions on value for money.

We aimed to replicate the CCA presented in the BB:0–2 trial, but there were differences in the populations of interest (e.g. the BB:0–2 trial focused on maternal costs), differences in data availability (e.g. no primary health-care data were available in the BB:2–6 study) and a lack of ‘rich’ data to accurately translate non-health-care items into costs. This lack of sufficiently detailed social care data in the routine data set meant that our original secondary objective to assess both health and social care resource use could not be fully achieved. The reported costs are limited to secondary health-care resource use against the primary and secondary outcomes. The current analysis shows costs to mother and child alongside child health and non-health outcomes, whereas the BB:0–2 trial focused on costs for the mother only, but consequences for both mother and child. In the BB:0–2 trial, only small differences in total health-related costs were seen in favour of the FNP, with the largest difference in secondary care resource use, particularly inpatient care. The BB:2–6 study findings are similar for the child, with the largest drivers of costs seen in hospital inpatient stays, but health-care costs showed only minor differences across both groups over the BB:2–6 study period.

The original BB:0–2 trial found that the FNP cost £1992.89 more per participant than usual care (when adjusted for baseline covariates, the difference was £1811, 95% CI –£2814 to £5547). 61 However, this did not take into account the total costs of delivering the FNP programme (i.e. time for family nurse visits and telephone calls were costed, but the involvement of other professionals in interacting with family nurses was not). This should be set against gains in benefits for children at 6 years of age, to determine whether or not the initial investment in the FNP is worthwhile.

The economic findings of this study are limited by the practical and analytical challenges of working with routine data, particularly with constraints in aligning resource use data other than HES in the BB:2–6 study to the BB:0–2 trial. These shortcomings affected the extent to which the full range of direct health-care costs could be reported, particularly primary care, and will be an underestimate of the full extent of costs over the medium term for both arms and, in particular, costs associated with social care and education.

Our cost-consequences approach has drawn on routine data (i.e. HES) to determine actual costs for each secondary care resource category and reported these against the range of consequences (outcomes), for the BB:2–6 study, across a range of sectors including social care and education. If suitably granular data were subsequently available, then further post hoc questions could be pursued to examine the relationship between costs and child maltreatment outcomes, especially with respect to non-health-care related resource use, for example social services interaction.

Our current analyses found differences in outcome linked to variation in visit dosage. We previously reported on visit frequency for women in receipt of the FNP during the original trial. 32 We compared these visit rates with those specified in programme fidelity targets, those observed in the implementation evaluation led by Birkbeck53 and those reported in the original US trials. 9–11 We concluded that visit completion in our trial exceeded that found in the implementation evaluation and the US trials, but fell short of programme fidelity targets. We also observed considerable between-site variation in the median number of visits received. However, recent developments in the FNP programme in England have addressed planned visit frequency, recognising that some women may benefit from more or less frequent visits. 77 Family nurses use a clinical tool (the New Mum Star) in combination with their clinical judgement to determine client need and adjust the frequency of home visits accordingly, including optimal timing for graduation. Although positively evaluated during the ADAPT programme,77 how this innovation is then linked to family outcomes will remain an important evaluation focus following commencement of its rollout to FNP sites in England from April 2020.

In this study, we identified a primary outcome and a cluster of related secondary outcomes relevant to the maltreatment focus of the commissioned call and predicted by the FNP logic model. In addition, we included secondary outcomes that were also predicted by the logic model. The planned analysis involved a large number of comparative tests, including for a priori subgroups. Therefore, we should be cautious, when interpreting the results, not to draw conclusions based on potentially spurious findings. However, there is a broadly consistent picture of findings across the maltreatment outcomes suggesting no effect. Similarly, there is a pattern of findings for educational attainment, which suggests an underlying beneficial effect. Although there are relatively few findings related to sample subgroups, those observed are similar to those observed in previous US trials. In each case, this provides confidence that the findings represent real programme effects.

A particular challenge for the original trial was evaluating an intervention for which there was a strong expectation of benefit from some policy and practice stakeholders and which was broadly implemented in England prior to trial results becoming available. We recognise that this was challenging not only for the research team but also for those delivering the programme. The evidence of only modest benefit from the trial generated debate about the selection of trial outcomes required by the funder and prioritised by the research team. The current evaluation was commissioned prior to the trial results becoming available and we have sought to include and report all potentially relevant outcomes available from routine record source. Some additional maternal-reported outcome data were included in our original funding request. However, although these were of programme relevance, they did not address the primary commissioning brief, which was focused on maltreatment, and we were unable to include them in our evaluation.

Although programme effects on developmental outcomes reached statistical significance, this does not necessarily indicate their clinical importance. For example, a public health perspective may value small effects for interventions being delivered at scale across a population. When effects are concentrated in population subgroups, the population likely to benefit most will be smaller. Therefore, the extent of ongoing FNP provision in England and the devolved UK nations will influence whether or not such levels of improvement are likely to be regarded as important. Other more focused educational interventions will also promote school readiness, reading and writing. The importance of such benefit from the FNP can be judged alongside such interventions. Particularly, this would be the case if the FNP programme effect was found to be restricted to just one (albeit important) domain. Much comparable evidence has been generated in North America; its relevance to the UK setting would need to be confirmed. For example, Chambers et al. ’s99 review of 32 studies of 22 early childhood programmes were all located in the USA, although all study populations were drawn from communities of high poverty. In Chambers et al. ’s99 review, average effect sizes for the most promising class of interventions were low to moderate (e.g. effect size of 0.15 for the effect of comprehensive programmes on literacy at the end of preschool). 100 Finally, complex home-visiting interventions such as the FNP aim to address a number of maternal and child domains over several years. This needs to be borne in mind when assessing the overall programme value.

Conclusions

There is little evidence of any important difference for a range of related maltreatment outcomes, even though children in the FNP arm who are assessed as in need are referred to social services sooner than children in the usual-care arm who are assessed as in need. These outcomes included designation as ever being a CIN, any referral to CSC, and injuries and ingestions resulting in emergency health-care attendance or admission. Similarly, rates of second pregnancies were equivalent across study groups, as were rates of child early educational attendance and provision of special educational support. Children in the FNP arm are more likely to exhibit a better all-round level of school readiness in their reception year. Adjusting for month of birth strengthens this effect. At KS1, more children in the FNP arm reach the expected standard for reading, an effect that is statistically significant when adjusting for month of birth. In planned subgroup analyses, programme effects at KS1 are larger for boys, but are statistically significant only for children of the youngest mothers (for mathematics and writing). Although the programme offers no apparent overall advantage for maltreatment prevention, it appears to provide support for child development, evident in reception and by the end of KS1. The use of objective routine data drawn together from a range of services has provided a clear picture of the medium-term impact of a specialist home-visiting service provided in England to teenage mothers expecting their first child.

Study Steering Committee membership

• Ann Louise Kinmonth (Chairperson)

• David Low

• Gordon Taylor

• Nina Biehal

• Rachel Tonkin

• Stavros Petrou

• Silvia van den Heijkant

NHS Digital data re-use statement

Copyright © (2019), the Health and Social Care Information Centre. Re-used with the permission of the Health and Social Care Information Centre. All rights reserved.

Contributions of authors

Michael Robling (https://orcid.org/0000-0002-1004-036X) (Professor and Director of Population Health Trials) was the chief investigator with overall responsibility for the design, co-ordination and delivery of the study. With co-investigators, he conceived, designed and led the original grant application. He led on drafting report chapters and made substantial contributions to synthesis and write-up of chapters in the report, commented on drafts and outputs of the study and facilitated stakeholder activities.

Fiona Lugg-Widger (https://orcid.org/0000-0003-0029-9703) (Research Fellow: Routine Data) was responsible for data acquisition, co-ordination and team management; contributed to the public involvement activities; led on the drafting of Chapters 1–3; and collated, reviewed and commented on the final report.

Rebecca Cannings-John (https://orcid.org/0000-0001-5235-6517) (Senior Research Fellow) was responsible for conducting the statistical analysis, led on the drafting of Chapters 4 and 5 and reviewed and commented on the final report.

Julia Sanders (https://orcid.org/0000-0001-5712-9989) (Professor of Clinical Nursing and Midwifery) contributed to the original grant application; advised on the management of the study, data analysis and interpretation; and reviewed and commented on the final report.

Lianna Angel (https://orcid.org/0000-0003-3962-9773) (Research Associate) carried out data cleaning, contributed to the public involvement activities, co-led on drafting Chapter 2 and reviewed and commented on the final report.

Sue Channon (https://orcid.org/0000-0002-5394-1483) (Senior Research Fellow) contributed to the original grant application; advised on the management of the study, data analysis and interpretation; and reviewed and commented on the final report.

Deborah Fitzsimmons (https://orcid.org/0000-0002-7286-8410) (Professor and Director of Swansea Centre for Health Economics) provided senior oversight of the health economics analysis; advised on the management of the study, data analysis and interpretation; and reviewed and commented on the final report.

Kerenza Hood (https://orcid.org/0000-0002-5268-8631) (Director of the Centre for Trials Research) contributed to the original grant application; advised on the management of the study, data analysis and interpretation; and reviewed and commented on the final report.

Joyce Kenkre (https://orcid.org/0000-0002-2067-9001) (Professor of Primary Care) contributed to the original grant application and public involvement activities; advised on the management of the study, data analysis and interpretation; and reviewed and commented on the final report.

Gwenllian Moody (https://orcid.org/0000-0002-2000-4944) (Research Associate) carried out data cleaning and reviewed and commented on the final report.

Eleri Owen-Jones (https://orcid.org/0000-0003-0850-4724) (Research Associate) contributed to the original grant application; advised on the management of the study, data analysis and interpretation; and reviewed and commented on the final report.

Rhys Pockett (https://orcid.org/0000-0003-4135-7383) (Senior Lecturer) was responsible for conducting the health economics analysis, led on the drafting of Chapter 6 and reviewed and commented on the final report.

Jeremy Segrott (https://orcid.org/0000-0001-6215-0870) (Senior Lecturer) contributed to the original grant application; co-ordinated the public involvement activities; advised on the management of the study, data analysis and interpretation; led on the drafting of Chapter 7; and reviewed and commented on the final report.

Thomas Slater (https://orcid.org/0000-0003-3840-2454) (Lecturer) Advised on the management of the study, data analysis and interpretation, and reviewed and commented on the final report.

All authors contributed to the design of the final report and approved the final version.

Publications

Lugg-Widger F, Cannings-John R, Channon S, Fitzsimmons D, Hood K, Jones KH, et al. Assessing the medium-term impact of a home-visiting programme on child maltreatment in England: protocol for a routine data linkage study. BMJ Open 2017;7:e015728.

Lugg-Widger F, Cannings-John R, Angel L, Moody G, Segrott J, Kenkre J, Robling M. Assessing the impact of specialist home visiting upon maltreatment in England: a feasibility study of data linkage from a public health trial to routine health and social care data. Pilot Feasibility Stud 2018;4:98.

Lugg-Widger FV, Angel L, Cannings-John R, Hood K, Hughes K, Moody G, Robling M. Challenges in accessing routinely collected data from multiple providers in the UK for primary studies: managing the morass. Int J Popul Data Sci 2018;3:2.

Lugg-Widger F, Hood, K, Robling M. Written Evidence Submitted by Centre for Trials Research, Cardiff University (DIG0006). Science & Technology Commons Select Committee Digital Government inquiry; 2018. URL: http://data.parliament.uk/writtenevidence/committeeevidence.svc/evidencedocument/science-and-technology-committee/digital-government/written/90379.html (accessed 18 November 2020).

Data-sharing statement

All data requests should be submitted to opendata@cf.ac.uk for consideration. Access to available anonymised data may be granted following review.

Patient data

This work uses data provided by patients and collected by the NHS as part of their care and support. Using patient data is vital to improve health and care for everyone. There is huge potential to make better use of information from people’s patient records, to understand more about disease, develop new treatments, monitor safety, and plan NHS services. Patient data should be kept safe and secure, to protect everyone’s privacy, and it’s important that there are safeguards to make sure that it is stored and used responsibly. Everyone should be able to find out about how patient data are used. #datasaveslives You can find out more about the background to this citation here: https://understandingpatientdata.org.uk/data-citation.

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, NETSCC, the PHR programme or the Department of Health and Social Care. 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 PHR programme or the Department of Health and Social Care.

Hospital Episode Statistics diagnoses codes

The codes in Tables 30–32 were used to select events from NHS Digital data sources for outcomes on injuries and ingestions and subsequent pregnancies.