Cultural adaptation of an existing children's weight management programme: the CHANGE intervention and feasibility RCT

Logistical issues with programme attendance

Several practical issues were highlighted as barriers to families attending sessions. Almost all participants wanted the location to be closer to them. A location that was some distance away was a particular concern for parents who had to take other siblings to the programme or collect them from school:

Well, it shouldn’t be too far away, it’s better if it’s closer because sometimes the car isn’t available and then I could walk too.

Interviewee 154, female, Pakistani, non-attender (interview conducted in Urdu)

If it’s closer, then it’s better because it saves time; because sometimes we have to collect the children, and both mother and father needed to attend, so we both went.

FG3, participant 2, male, Pakistani, completer (FG conducted in Urdu)

They did send out appointment but it was quite far in the distance; then I couldn’t actually travel ’cause I had the small children, as well.

Interviewee 114, female, Pakistani, non-attender

The reason why I couldn’t make it is because I’m not driving, so having to travel to the place and then coming back with another small child, at the time I think she was a baby, was really difficult for me . . . It was just that really, I really want to go as well.

Interviewee 144, female, Pakistani, non-attender

Many participants, regardless of whether or not they had attended, thought that their local school would be a convenient and familiar venue and would, therefore, encourage families to attend. However, this was not universal and some participants thought that a new environment might be more stimulating for children.

From FGs 1 and 2 came the following opinions:

I think if you go through the school it’s better. Everybody has to take their children to school. So if in the morning, when they’ve gone to school to drop their child off or in the afternoon, if the teachers come forward and talk to the parents then like ‘this is what’s happening and if you would like to attend’ maybe they would be, because everybody takes their kids to school and that would be a good way of catching them.

FG1, participant 3, female, Bangladeshi, completer

But the lady that said about the school that was really good like, that just clicked onto my brain and there should be more sessions in school I think and you will get more turn out like with the parents and stuff.

FG1, participant 1, female, Pakistani, completer

I think it should be in different areas, because they get bored in their own schools, because the children develop their confidence going to a new setting, because they know why they’re attending, this is a better idea.

FG2, participant 4, female, Pakistani, completer

The timing of the programmes was often difficult, with participants commenting on other commitments that could prevent families from attending. Of note was the daily attendance at the mosque after school for some children from these communities, which would prevent them from attending sessions at this time. The suggestion of running programmes at the weekends was made by many participants. It was generally felt that this would be more convenient for families:

I think that it’s about timing because some people have young children and others are older so they need to pick them up from school, others are in college so they need to collect them, so I think it’s about timing.

FG3, participant 1, female, Pakistani, completer (FG conducted in Urdu)

. . . the timing and, you know, it’s not – and town is like, you know, busy and . . . so . . . especially after 4. It’s really hard. They have, like, their own activity. Mosque and everything. Tuition. This and that. So that’s why I couldn’t.

Interviewee 133, female, Pakistani, non-attender

Weekends, because after school they go to school and mosque, all Muslims, even Indian or Bengali or Pakistani, every Asian, children attend mosque after school.

Interviewee 139, female, Pakistani, non-attender

Well, you know this weekend, it would be better, the children would be home and you could take them instead of missing them and they’re taking time off from school.

FG1, participant 1, female, Pakistani, completer

Several participants spoke about running the programme during school time and the need for children to take time away from school to attend. Generally, this was felt to be something that was important enough for a child to miss school for and that schools would allow it. However, in some cases it was a deterrent to attending, even though schools allow absence for health-care appointments:

I’m sure if it’s a school day, the school would give him an hour or so just to go into, it’s regarding health isn’t it, so I’m sure school would allow him to go for an hour or do the programme in the weekend like Saturday/Sunday.

Interviewee 129, male, Bangladeshi, non-completer

Yeah, I was just saying that, they need to go to every session, even though I know it’s school time.

FG1, participant 1, female, Pakistani, completer

I was upset because I couldn’t go. I couldn’t have the time, I couldn’t take my – especially with schools now where they’re strict on the children, you know, attending school and not missing days. So it was hard for me.

Interviewee 104, female, Pakistani, non-attender

The requirement to attend to siblings was also raised. Some parents reported that having very young children in the family prevented them from attending; however, some participants in the completer group reported that younger siblings were present in the sessions and this did not cause any problems:

When I started receiving letters and phone calls from yourselves then I realised that there might be support. My daughter says to me that ‘mamma I want to go for exercise’ . . . I told her that I couldn’t go with her because I have other children. I have small children, my youngest is 2 years old.

Interviewee 109, female, Pakistani, non-attender (interview conducted in Urdu)

I didn’t have younger children but other families had young children with them. And they sat too, it wasn’t that the younger ones couldn’t sit and listen too.

FG2, participant 4, female, Pakistani, completer

Finally, parking near the venue was raised as an issue by some participants and, in some cases, was a deterrent to attending further sessions:

It’s not far but it’s like finding parking is the worst problem, that was the biggest problem for me not attending. The first day when we went, we were going round and round and then we managed to find a little space. The second time when I went I couldn’t find a space and I just said ‘oh enough’.

Interviewee 129, male, Bangladeshi, non-completer

Language barriers and programme attendance

Some parents who were unable to speak English reported difficulties in communication at the first contact, and for some this prevented them from attending:

Someone rang on my home phone speaking English and inviting me to attend the programme but I was asking her if I needed to take my daughter with me, because my English is not very good; but she could not understand what I was trying to ask her. I was asking if I needed to take my daughter with me. She couldn’t understand me so she said she will call me back but we never heard from her again.

Interviewee 150, female, Bangladeshi, non-attender (interview conducted in Bengali)

English-speaking participants also reported observing difficulties experienced by the non-English-speaking parents who attended the programme. However, some participants who completed the programme felt that non-English-speaking parents were able to understand the programme content, either because of the way the information was delivered or because they had brought a family member to interpret for them:

Yes, because I’ve seen some parents there that are, like, it was hard for them to understand and I was doing a lot of explaining to them as well.

Interviewee 123, female, Pakistani, non-completer

I don’t know English, they were English, but I understood everything because of the way they explained it, with gestures and all the information so that we could understand.

FG2, participant 2, male, Pakistani, completer (FG conducted in Urdu)

So was there a translator there?

No. Because at first I didn’t really mention it because my daughter was with me and so I didn’t have any problems because my daughter would speak for me and she’d translate what I was saying back to them about what to do, etc.

FG3, participant 1, female, Pakistani, completer (FG conducted in Urdu)

In general, participants felt that the availability of interpreters (which were provided in the First Steps programme) would overcome the barriers to participation that were related to language:

If it’s local and an interpreter is available. We would like to attend because it will help our child. I know I can get advice and help on diet and exercise.

Interviewee 150, female, Bangladeshi, non-attender (interview conducted in Bengali)

My niece had taken her son to First Steps programme, but she herself didn’t understand English, right? . . . She told me what was there, but she felt left out, as a parent – saying that, you know, ‘If there’s enough information for me, because I can’t read,’ she said, ‘and I can’t understand, then it would have been easier if there was somebody to explain to me’.

Interviewee 113, female, Pakistani, non-attender

And language difficulties. Not for yourself but was there any ladies in the class that you think language was a barrier?

Well they brought someone along with them or they got the children to interpret for them.

Interviewee 1036, female, Pakistani, completer

Programme structure and delivery

The course duration of 5–7 weeks was generally thought to be appropriate by most families, although a few participants thought that more sessions would be helpful. The session duration of 1 hour was raised as an important consideration among some families, especially if they were required to travel some distance. It was felt that if they had made the effort to attend, the session duration should be longer:

It’s not reasonable for me going and going back and coming back, so that is an issue, as well. So if the hours were extended, like an hour and a half or 2 hours, that would be reasonable.

Interviewee 113, female, Pakistani, non-attender

I think 7 weeks is OK, to be honest, yeah. That’s not a problem. I think that’s just about right to be honest, yeah. Because if you make it too long, probably get a bit boring wouldn’t it.

Interviewee 143, female, Pakistani, non-attender

Aspects of the programme that deterred families from participation were the didactic nature of the programme sessions and the presence of too much paperwork. Participants disliked just sitting in sessions being given information and wanted a much more interactive format:

I thought it was going to be like kind of activities where they actually show you what kind of activities you can do with your children, what kind of sports and obviously get them interested in them [sic.] kind of activities. But obviously it was like just basically information just sit there and obviously giving us information about what kind of nutrition and diet and exercise and everything but I thought it was going to be more physical than obviously classroom based.

Interviewee 142, female, Pakistani, non-completer

I think there was a bit too much paperwork and what it is, she was giving out the information, yes she was trying her best, but I think the way she was delivering it everyone was like going half asleep . . . because some parents don’t take it in as that, and it’s like they need to get up and do.

Interviewee 107, female, Pakistani, non-completer

Those who attended or completed the programme valued messages being presented in a visual way, and participants’ experiences of interactive activities were viewed very positively:

The visual, it was the visual things really that she all brought the visual things and that really like makes it more better understanding then like you know.

FG1, participant 1, female, Pakistani, completer

I was quite impressed with that because four spoons of sugar, I will just, in my head it’s four spoons of sugar, but when you actually see it in a packet it’s got four spoons in it, then you think my life it’s that much sugar, you know?

Interviewee 129, male, Bangladeshi, non-completer

[Participant talking about a related workshop that was not delivered as part of the main programme] It wasn’t really cooking it was just ready-made wraps, and you would just put salad in it, and we needed to cut it and put it in and whatever you need to put in there like butter they had brought along with them. So we cut it up, and the children cut it up and made them and then you have a look. In this way I think the children enjoy it too, so they understand that this is happening for them, so it sinks into their minds that if they do this then it will be of benefit to them.

FG3, participant 1, female, Pakistani, completer (FG conducted in Urdu)

The great majority of parents across all three participant groups felt that the programme would be more valuable if children attended all sessions:

It would have been a bit more ideal if the kids were more involved. That’s what I would – because then yes we need to have that understanding, but I believe the kids need to understand what they should have and the intake and how it’s with their body.

Interviewee 107, female, Pakistani, non-completer

I realised it was only first and last session that he has to attend, so I wasn’t really pleased with that, because I was thinking he needs to go there like to other sessions.

Interviewee 103, female, Pakistani, non-completer

They also felt that their children would take more notice if messages were given by an ‘outsider’ rather than their parents:

Because sometimes children don’t listen to their mum or dad but they listen to the teacher or outsider.

FG4, participant 1, male, Pakistani, completer (FG conducted in Urdu)

. . . although my daughter does listen to me. I think getting the information first-hand would make a big difference. So it’s important for both mother and child to attend.

Interviewee 150, female, Bangladeshi, non-attender (interview conducted in Bengali)

There was also the view that the children need to understand why it was important to eat healthily or do physical activity, as this would be more likely to lead to a change in their behaviour. One participant felt that children in the group who lost weight would provide motivation for other children:

I think children should go [to] every session because then, you know, well how I look at [it] is if the children don’t go and then we’re telling [them] ‘oh you’ve got to do this, this’, they probably think we just sometimes, most kids, they will think oh just my parents being horrible to me, my parents, but when they go into classes and they see these other people they don’t know who are actually telling them, then they will listen more because they will think: hang on if I don’t know the chap there was telling me, so I think my dad is right, so yeah OK I’ll try that.

Interviewee 129, male, Bangladeshi, non-completer

If the children are involved then they will take notice of how hard they have worked, and if that child’s weight reduces then the other children are listening too so it will benefit them too.

FG2, participant 4, female, Pakistani, completer

They [children] need to go to every session, even I know it’s school time.

FG1, participant 1, female, Pakistani, completer

So if like you know if like if these sessions are done but then it’s explained to the kids a little bit more about ‘this is what you need to do because it’s your life, you’re going to be affected in the future’ and stuff like that then it might help them.

FG1, participant 3, female, Bangladeshi, completer

Participants were generally positive about attending a group programme with other families and sharing experiences. Some really valued the sense of community that they gained from attending the group sessions:

I think this is a really good idea like when you go to a talk then you get to hear the views of others and that has an effect on you.

Interviewee 109, female, Pakistani, non-attender (interview conducted in Urdu)

There was [sic.] different community families, and friendly, Indian, Bengali, English, Sikh, and children mix up, and share their experiences.

FG2, participant 4, female, Pakistani, completer

Because it was the same lady [facilitator] for all five sections, and she nicely laughs and you know and mostly my son was happy you know and when different communities people sit and talk and like it was like a challenge between everyone and she used to push them to compete.

FG2, participant 4, female, Pakistani, completer

Programme content: weight status

The programme’s focus on weight loss was a barrier to some families’ participation. Some parents who never attended the programme did not identify their child as being overweight or that their weight was something that needed to be addressed but they were interested in helping their children to become more active:

I don’t see it as overweight, ’cause I know what they eat. I know they’re not eating the wrong food. Yes, they’re less active, but what do you do?

Interviewee 108, female, Pakistani, non-attender

My daughter, she’s not really overweight, it’s just that her weight has gone a bit over the mark.

Interviewee 104, female, Pakistani, non-attender

I mean, if you look at my son, he’s not overweight, I mean, he’s quite, for his age, he looks bigger than his age, I mean, he doesn’t look like really big or anything but he is quite heavy.

Interviewee 144, female, Pakistani, non-attender

Some parents who attended some or all of the programme reported that their children were sensitive about their weight and did not like being weighed. One parent who completed the programme reported that she did not have the support to attend from other family members:

I know it was weigh in and there was less time but with the kids I think if they approach them a bit differently because nowadays kids are very, very sensitive and every sort of thing just sticks in their head and I think, you know, ‘oh God, mum’ and then in school they’ll have that – because they had to come out of school and then it’s them like ‘oh, we’re going for the weigh in’ and she was embarrassed to even tell her brother and sisters what she was going for.

Interviewee 107, female, Pakistani, non-completer

My family members say that what’s the point of you going to the programme, and how it takes a lot of time and that there aren’t going to be any benefits. I said that they may not see the benefits but I do, because I can get my daughter’s weight down about 2/3 kg in 1 week if I focus on this information.

FG3, participant 1, female, Pakistani, completer (FG conducted in Urdu)

Programme content: nutrition

Participants, particularly non-attenders and non-completers, reported that they felt that the course offered no new insights for them. Several parents thought that their knowledge of what a healthy diet consisted of was good, and they already knew or had been previously told what their children should be eating. However, among the completers, some participants felt that their knowledge of the nutritional content of foods had significantly improved, and they particularly valued when they were also advised how to address nutritional content in their children’s diets:

I thought it would be just like talking through healthy and unhealthy but myself, I always look on the internet for healthy options, healthy meals and you know what’s good for me, what’s not good for me. So I’m constantly on the internet, right? So I thought I probably know it anyway.

Interviewee 104, female, Pakistani, non-attender

We went on the first session. The minute that plate came up and those sugary – you know, those little packets and everything, we thought, ‘Oh, we’ve been there, done that. Forget this.’

Interviewee 121, female, Pakistani, non-completer

What they were telling us on that first day, it’s like more or less we know it, you know, doctors and the nurses and surgery, they’re telling us what to do.

Interviewee 129, male, Bangladeshi, non-completer

But the way they explained everything it was very interesting. I didn’t know just a bottle of water with lemon juice had like so many rounds of sugar in there and all that stuff and like they said biscuits you think that’s the healthy option, actually it isn’t. You know like so it was quite an eye opener.

FG1, participant 3, female, Bangladeshi, completer

Because they brought a lot of material about foods with them, like sweet packets, crisps, sugar, etc., all these things were there and how much sugar was in them. How much salt is in things and how to swap these things and it will be effective. And I did this 100% and it took effect.

FG3, participant 1, female, completer (interview conducted in Urdu)

The relevance of the programme content to the food that families typically consumed was explored with the participants. Participants reported that they and their children ate both Western and South Asian food and that there needs to be a focus on both in the programme:

I think they should talk about both [South Asian and Western food]. We do eat Asian food a lot but my children like both so it would be beneficial to get advice on both.

Interviewee 150, female, Bangladeshi, non-attender (interview conducted in Bengali)

We do eat fish and we do eat baked beans and stuff, but we do eat our own food as well, so we need education on our own food.

Interviewee 113, female, Pakistani, non-attender

We eat a range of foods and my daughter likes eating food like this. They eat Pakistani food too but also English foods that are vegetarian.

Interviewee 109, female, Pakistani, non-attender (interview conducted in Urdu)

From FG1 the following was noted:

And what sort of foods would you like to learn about in cooking, westernised or traditional or a bit of both?

A bit of both, yeah.

A bit of – the children do have both.

FG1, participants 1 and 4, female, Pakistani, completer

They get to have, they get bored with this type of food all the time, they want to try something different. So that would be like a mixture really.

FG1, participant 4, female, Pakistani, completer

There was a concern among several participants that related to the consumption of ‘junk’ foods and takeaways:

She eats a lot of chocolates, sweets and crisps, she eats a lot of takeaways, like burgers, drinks a lot of fizzy drinks, she eats a lot of this stuff. Stuff like chapatti and curry, she eats less of.

Interviewee 154, female, Pakistani, non-attender (interview conducted in Urdu)

But, the temptation in this area is that we have cheap takeaways, and they are very tempting. You know, you think, ‘Why cook?’ And, you know, we’re tempted to, you know, just, ‘Oh, it’s an easier option. We’ll get chicken and chips. It’s only £1.50.’ So, you know, that’s why the weight is creeping up with children.

Interviewee 113, female, Pakistani, non-attender

Some participants commented that they would like to learn how to cook South Asian foods in a healthier way. However, one participant who had completed the programme commented that although she could change certain aspects of her child’s diet, she was not going to change the way she prepared traditional foods:

I want to know, if I’m making a chapatti, how many calories are in there? You know. If I’m making a curry – it’s really hard to – how many calories – you know, hand-size or, you know, it’s hard – in reality, it’s really, really hard. Maybe do a cooking session; say, ‘This is a portion.’ You know. ‘It’s right.’ Maybe do it that way . . . or even, like, give recipes on maybe even healthier Asian food, rather than – fair enough, do the English food, as well. OK, we have it once a week or whatever. And that’s ovenly – oven-made or it’s grilled. But help us with the type of food that we’re eating. Where are we going wrong?

Interviewee 108, female, Pakistani, non-attender

Yeah, because if I change using less oil, I can’t taste my curry without oil, since I was 3 and have grown up, I can’t change that but I can swap other things, fat milk with semi skimmed and white with wholemeal breads but I can’t change my curries.

FG2, participant 1, female, Pakistani

Some participants identified that shopping for healthy food was an issue, and that education about food labelling and purchasing healthy food options was required:

When you buy the shopping, more labelling, more information, because I understand what they say sometimes there’s energy and then the parents, some get confused because obviously and some English is not even there, so if they can like give a bit more which is more better and which is more healthy, like [drink brand], because I didn’t pick it up from there, [drink brand] does have a lot more sugar than we thought.

Interviewee 107, female, Pakistani, non-completer

Programme content: physical activity

Participants almost universally wanted some physical activity content in the programme. It was acknowledged that the facilitators spoke about physical activity but parents felt that the children should be doing physical activity in the programme sessions:

They should do more activities like, you know, physical activities to help them and not just concentrate on the food side.

Interviewee 123, female, Pakistani, non-completer

If they could like have a meeting for half an hour and then integrate like another half an hour to do the sports, I think that would be good as well.

FG1, participant 3, female, Bangladeshi, completer

I think that if you are doing this programme then you need to put some exercise sessions in it too, whatever is best for children . . . if you have the space then you should have exercise programmes in it too.

FG3, participant 1, female, Pakistani, completer (FG conducted in Urdu)

In response to the above: it’s exactly like what the sister [other participant] is saying. In terms of food, there’s calories and how much you should eat but besides this exercise is really important.

FG3, participant 2, male, Pakistani, completer (FG conducted in Urdu)

Several barriers to children undertaking physical activity were identified, including busy families lacking time, a lack of local opportunities and the perception of dangerous environments, particularly in terms of outdoor activities. Some participants suggested that practical advice about physical activity that children could do at home would be useful, which would overcome several of the identified barriers:

We rarely get to go to the park unless it’s a hot summer’s day. It’s just busy.

Interviewee 108, female, Pakistani, non-attender

There’s just nowhere for us to send them where they can get exercise. Whether they can play football or cricket or anything, they should do something. And I would enrol them there.

Interviewee 155, female, Pakistani, non-completer

I want to ride a bike . . . and my husband goes ‘can you see how dangerous it is, the cars out there’.

Interviewee 112, female, Pakistani, non-attender

And you can’t let them go to the parks alone. And it’s just round the corner but you just can’t . . . You just can’t let them out, ’cause a lot has been, you know, happening around here.

Interviewee 108, female, Pakistani, non-attender

And you can do something at home as well, children sitting down, it’s better to tell them to walk like 10 times on the stairs, up and down. That’s a good exercise for them.

FG2, participant 1, female, Pakistani, completer

Several participants also identified that they used cars when they felt that they should be walking with their children:

My sister gets into the car and drops them off to the secondary school, you see. But they need that exercise. They need to learn how to walk, as well. You know, the car is very convenient, but it’s really bad for the kids.

Interviewee 121, female, Pakistani, non-completer

Parents’ influence over their children

Among the parents who had completed part or all of the programme, a common theme was that even when they implemented changes in the home to try and encourage a more healthy diet, children would find ways of circumventing this. In some cases, parents also admitted to ‘treating’ their children to something unhealthy:

I’ve tried to cut down. You know they showed us a certain plate of vegetables, that’s how much and all that stuff and I’ve tried doing that, I’ve really tried getting into it but I find that he sneaks behind me, he goes in the kitchen and helps himself.

FG1, participant 3, female, Bangladeshi, completer

When he goes to my mum’s house, he helps himself a lot and then when we go to family, like, he doesn’t listen, he helps himself a lot.

Interviewee 103, female, Pakistani, non-completer

But the drink wise, he does drink sometimes fizzy drink and I’m not going to deny that I do bring sometimes, I feel bad, they like it, right, so just drink a bottle and give it to them, I say ‘look hide it’.

Interviewee 129, male, Bangladeshi, non-completer

Anthropometric assessments

Height, weight and body fat percentage measurements were collected following standard operating procedures (see Appendix 6). Participants were measured in light clothing without socks and shoes and any headwear was removed. If the participant was wearing religious headwear that they did not wish to remove, it was measured and then deducted from the height measure. Child height measurements were taken on inspiration, and in duplicate, using a Marsden Weighing Group© Leicester Height Measure (HM-250P). To allow for measurement error, a third measurement was taken when the difference between the two measurements was > 0.4 cm. The two closest of the readings were averaged to give the definitive measurement.

Weight and body fat percentage measurements were taken using Tanita^® body composition scales (Tanita^® BC-420MA body composition scales). Participants were asked to pass urine before stepping on to the scales to minimise the effect that a full bladder could have on the fat percentage measurement. BMI was calculated by dividing weight (kg) by height squared (m). BMI z-scores were calculated for BMI and fat percentage using the lambda–mu–sigma (LMS) method and UK reference data. 44,76

Waist circumference was measured 4 cm above the umbilicus (a measurement point identified to be the most valid and pragmatic in overweight children77) using a flexible steel tape measure. Children were asked to raise their clothing to access the waist; however, if they refused, an option was given to take the waist measure over thin clothing. Waist measurements were taken at the end of a normal expiration and were taken in duplicate. When the difference between measurements was > 0.4 cm, a third measurement was taken. The two closest of the readings were averaged to give the definitive measurement. The LMS method and UK reference data78 were used to produce an age- and sex-specific waist z-score from the definitive waist circumference measurement value.

Questionnaire assessments

The researchers verbally administered a number of questionnaires to children and recorded the responses (see Appendix 7). Quality of life was assessed using two instruments: the Pediatric Quality of Life Inventory (PedsQL) Generic Core Scales version 4.0 and the Child Health Utility 9D (CHU-9D) questionnaire. PedsQL is a validated questionnaire consisting of subscales measuring physical, emotional, social and school functioning. 64,65 These aspects of quality of life are considered separately and all four are combined to assess overall quality of life. Age-specific versions of the PedsQL were used according to the child’s current age. Items were read to the children and responses were obtained either verbally or by using pictorial scales with younger children. PedsQL Likert scales were converted to 0- to 100-point scales, in which higher scores indicate a better quality of life.

The CHU-9D is a validated quality-of-life measure,66–68 which is administered for use in health economic analyses. It is a preference-based measure of health-related quality of life for use in children. It comprises a descriptive system and a set of preference weights, allowing the calculation of quality-adjusted life-years for use in a cost–utility analysis.

A figure rating scale, developed by Collins,69 and adapted by Rand and Resnick,70 was used to assess body image. This scale consists of sex-specific drawings of nine prepubescent figures ranging from very underweight (value = 1) to very overweight (value = 9). Two versions (light skinned and dark skinned) were developed for use in the study. Researchers used the version that was most appropriate for the child’s skin colour. Children were asked ‘Which picture looks the most like you look?’ and ‘Which picture shows the way you want to look?’ to assess ‘self’ and ‘ideal self’, respectively. To calculate children’s body dissatisfaction, the ‘ideal self’ score was subtracted from the ‘self’ score, giving a value of between –8 and +8. A score of 0 indicated body satisfaction, negative values indicated that the child would like to be larger and positive values indicated that the child would like to be thinner.

To assess children’s patterns of food intake, the Children’s Dietary Questionnaire was used (see Appendix 8). This parent/carer-completed 28-item questionnaire is a measure of intake patterns of a variety of healthy and unhealthy foods and is validated for assessment of intake patterns in children aged 4–16 years. 71 Four food group scores are calculated from the items: fruit and vegetables, fat from dairy, non-core foods and sugar-sweetened beverages. As the questionnaire was originally developed in Australia, minor adaptations were made, with input from the Parent Advisory Panel and the co-investigator team, to ensure applicability to the diets of the UK-based ethnically diverse study population. Parents were asked to complete the questions independently unless language or literacy support was required. In these cases, the researchers completed the questions with the parents.

Physical activity assessment

Objectively measured free-living individual physical activity was assessed using triaxial accelerometers. At each assessment period, during the home data collection visit, children were asked to wear an accelerometer continuously for 7 days on their non-dominant side, except when sleeping. Two types of accelerometers were used in the study: the wrist-worn GENEActiv© (Activinsights Limited, Kimbolton, UK) and the waist-worn ActiGraph© GT3X+ (ActiGraph, Pensacola, FL, USA). The purpose of including two different accelerometer types was to assess which gave the greatest level of participant compliance and data completeness. GENEActiv monitors are typically worn on the wrist and provide raw acceleration data. ActiGraphs are typically worn on the waist, have been commonly used in research with children and have been validated for use in this age group. 79–83 They can also provide raw acceleration data. At the baseline assessments, researchers assigned children either a GENEactiv or ActiGraph monitor at random. The children were then fitted with the same monitor type at the follow-up time points.

Both devices were set to record at 100 Hz in 60-second epochs. Data were analysed using the GGIR version 1.4 package developed in R version 3.3.1 (The R Foundation for Statistical Computing, Vienna, Austria; www.r-project.org; accessed 9 May 2016) through the University of Birmingham BlueBEAR High Performance Computing Service (www.birmingham.ac.uk/bear; accessed 9 May 2016). This package autocalibrates the raw triaxial accelerometer signals (x, y and z) to produce one omnidirectional value, the gravity-subtracted signal vector magnitude (SVMg; mg), using the Euclidean norm minus one (ENMO) formula [i.e. SVMg = √(x² + y² + z²) – 1]. Further information on the GGIR package is detailed at the following web page: (https://cran.r-project.org/web/packages/GGIR/GGIR.pdf; accessed 9 May 2016). A valid day’s wear was defined as > 10 hours of wear time in a 24-hour period. Device- and location-specific ENMO cut-off points were employed to estimate minutes spent in moderate activity (equivalent of four metabolic equivalents), vigorous physical activity (equivalent of six metabolic equivalents) and moderate to vigorous activity (activity at intensity levels over four metabolic equivalents). These were 359.7 mg (moderate activity) and 695.8 mg (vigorous physical activity) for GENEActiv monitors and 249.9 mg (moderate activity) and 464.6 mg (vigorous physical activity) for ActiGraph monitors. 84–86

Other data collection

In children aged ≥ 8 years, pubertal status was assessed using a simplified version of the Tanner scale. 87 Researchers were asked to indicate if there was any sign of breast development (females) or facial hair (males). In addition, parents were discreetly asked if menstruation had begun for female children. The Parent Advisory Panel was consulted on this approach to ensure its acceptability to participating children and parents.

The BCHCT children’s weight management team provided information on date of birth, sex and postcode for the participating children. This information was verified at the initial home visit. Parent/carers reported their child’s ethnicity, religion and language spoken. The postcodes were converted to the Index of Multiple Deprivation (IMD)88 2015 scores, a measure of small-area deprivation, which was used as a proxy for socioeconomic status. Participants were categorised into five groups using quintile cut-off points for England, so that group 1 included all individuals living in an area that is classified as being in the 20% most deprived areas in England, and group 5 included all those living in areas that are classified as being in the 20% least deprived areas in England.

Anthropometric assessments

Height, weight and body fat percentage measurements were conducted with parents and carers who gave consent using the previously described measurement protocols (see Appendix 6). The BMI score was calculated by dividing weight (kg) by height squared (m).

Questionnaire assessments

Parents were given a questionnaire booklet and asked to complete it (see Appendix 8). Researchers provided assistance to parents when necessary. If a parent did not speak English, it was ensured that a community researcher with relevant language skills undertook the data collection visit so that they could verbally translate and complete the questionnaire with the parent. If participants spoke a language that was not spoken by the community researchers, an interpreter accompanied the researcher and verbally translated questions and participant responses, which were then recorded by the researcher.

At baseline, questionnaires included a range of questions to collect sociodemographic information, including parental ethnicity, religion, first language, place of birth (and when they moved to the UK if applicable), age when leaving full-time education, highest educational qualification and employment status.

At all time points, a number of questionnaire subscales relating to aspects of parenting style, self-efficacy and feeding practices were included in the parent questionnaire booklet. Parenting style was assessed using the authoritative parenting dimension of the Parenting Styles and Dimensions Questionnaire. 73 This dimension consists of three subscales: connection (five items), regulation (five items) and autonomy (five items). Subscale scores were calculated individually and summed to give a total authoritative parenting score. Higher scores represent a more authoritative parenting style.

Parental self-efficacy was measured using the Parental Locus of Control scale. 74 This scale consists of 10 items, which were summed to create a total self-efficacy score. Higher scores represent lower parental self-efficacy.

Nine subscales of the Comprehensive Feeding Practices Questionnaire (CFPQ) were used to measure a selection of parental feeding practices. The CFPQ has been shown to be valid in children up to 12 years of age and in varied cultural contexts. 75,89 However, to keep respondent burden to a minimum, only selected subscales of the CFPQ were included in the parent questionnaire. These were: (1) child control, (2) encourage balance and variety, (3) environment, (4) modelling, (5) monitoring, (6) restriction for health, (7) restriction for weight control, (8) teaching about nutrition and (9) involvement. Each subscale contains between three and eight items, totalling 39 items. Higher scores represent greater use of each practice.

All items from the three questionnaire instruments described above were answered on Likert scales from 1 to 5 points. Items indicated as needing to be reverse-scored by the relevant instrument instructions were reversed accordingly. For ease of interpretation, scores for all items in each subscale were summed and divided by the number of items, creating a score range of 1–5 points for each subscale. If one (3- to 5-item subscales) or two items (6- to 15-item subscales) were missing for any responder, the subscale was standardised using the number of items answered as the denominator. When more than 1 or 2 items were missing, a score was not calculated.

Anthropometric assessments

Height, weight and body fat percentage measurements were taken for any other consenting/assenting family members aged > 4 years who were present at the data collection visits. The previously described measurement protocols were used to conduct these measurements (see Appendix 6).

Family behavioural assessment

The Family Nutrition and Physical Activity (FNPA) questionnaire is designed to assess family behaviours and environments related to children’s nutrition and physical activity. 72 The questionnaire has 20 items overall and 10 subscales (two items each). The subscales are (1) family meals, (2) family eating practices, (3) family food choices, (4) family beverage choices, (5) restriction and reward, (6) screen time, (7) creating a healthy environment, (8) family activity, (9) child activity and (10) family schedule/sleep routine. All items of the FNPA were included in the questionnaire booklet for completion by parents/carers.

Sensitivity analyses

For a variety of reasons (incomplete data collection, attrition, etc.) the numbers of participants included in the models to explore differences in outcomes between intervention and comparator arms were lower than the total number of study participants. For some outcomes, the number of missing data was substantial. Therefore, to explore further the differences between study arms, two imputation techniques were employed. First, the baseline observation carried forward technique was utilised, in which the missing follow-up value is replaced with the observed baseline value. 96 This technique allows a conservative effect estimate to be generated. However, concern has been raised over the ability of single-imputation methods, such as baseline observation carried forward, to produce unbiased estimates of variance96 and there is an overconservative assumption that study non-completion is synonymous with no effect. 97 Therefore, we used multiple imputation techniques in a second sensitivity analysis. Imputation was conducted for each outcome separately. For the anthropometric and physical activity outcomes at T1 and T2, the following items were included in the imputation process: the outcome of interest, the baseline (T0) value of the outcome (when available), other anthropometric and physical activity measures taken at the relevant time point (i.e. T1 or T2), completion status, pubertal status, age, sex, ethnicity and IMD score. For the questionnaire-based outcomes at T1 and T2, the following items were included in the imputation process: the outcome of interest, the baseline (T0) value of the outcome (when available), completion status, pubertal status, age, sex, ethnicity and IMD score.

We allowed for clustering in the multiple imputation procedure. The procedure involves fitting a conditional model for each variable with missing data in which the variable is linearly regressed on all other variables using mixed-effects linear regression (those with and without missing data). It then uses a Gibbs sampling approach (100 iterations), updating each set of parameters in turn, conditional on the others. A mixed-effect linear regression model was used to analyse each continuous outcome variable conditional on the imputed data. Rubin’s rule is used to pool the effect estimates of 10 sets of imputed data. 98 We transformed any variables that showed marked non-normality. Transformations used in the imputation process were consistent with the main analysis. These multiple imputation models were implemented in Stata and REALCOM-Impute (Centre for Multilevel Modelling, Bristol, UK).

Overall experiences

Both facilitators reported that they enjoyed delivering the adapted programme, which was consistent with the feedback they gave during the running of the programmes. They both acknowledged that the programme was very different from the standard programme that they had previously delivered. Much of the facilitators’ praise for the new programme focused on the more interactive and flexible delivery, which was a significant change from the standard programme (although there were interactive elements in the standard programme; see Appendix 4). The facilitators also felt that the families attending responded well to the interactive nature of the programme:

I think a lot of the aspects of the course worked brilliantly and I really enjoyed the interaction of it so overall I enjoyed it and I much prefer it as a course.

F02

It was a nice refreshing change to see that we could facilitate rather than actually talk, erm, some of the families to death at times so it was, it was I would say nice. Erm, and as I, like I said it was a refreshing change to sort of try and deliver something new. Erm, and to be honest I, I would say that it was, erm, a pleasant I would say response from a lot of the families as well.

F01

With the new programme I would say that there was a lot more opportunity for the families to get involved so a lot more sort of, erm, I would say practical activities that we could get them involved into as well, so that was nice. Although we did have some practical things in the old programme, erm, I would say that maybe some of the things we didn’t sort of hit the nail on the head with certain things which you guys [researchers] did.

F01

Both facilitators highlighted that the programme sessions provided a good environment for social interaction between participants and that parents would share experiences and support one another in sessions. This meant that their role was much more facilitatory and less directive than previously:

There, erm, a better I would say, erm, social environment between I would say the participants because we gave them I think more opportunities as well though in this course. Although they still had opportunities in the older course, I would say they did have a few more extra ones here where we’d bring in the games and things as well. So I think it was a, it was a nice chance for them to, I would say more chances for them to actually gel together and, and, and speak to one another.

F01

What tended to happen was one parent would say ‘from last week do you remember talking about this? And blah, blah, can you tell me a bit more about it?’ And then another parent would join in and go ’you know my daughter does that and then for me when . . .’ it worked brilliantly. I could just sit back and let them do it and for the most part a lot of good discussion was had. Certainly in that when the children were removed and they went off to play in the physical activity session when it’s just me and the parents and that’s when it works beautifully. If one parent does pipe up with something and then they all start talking and I liked that because it took it away from me going ‘right, do you do this or do you do that?’.

F02

The provision of new, high-quality printed materials (display boards, participant folders, etc.) was well received by the facilitators. They felt that it gave the programme a more professional edge and helped the families feel that they were important, thus encouraging their engagement with the programme. The facilitator delivery guide was also highly valued:

I think because the [display] boards themselves which I love, the materials and everything fantastic, the boards are brilliant . . . and just the whole fact that they’re getting materials you know the ones that we were giving [in the standard programme] were very good but these were of a quality that’s kind of far in excess of the ones that we were giving previously and I think that kind of gives them a sense of ownership and importance and they’re coming to something and a little bit of excitement and involvement for the children.

F02

We’ve loved the resources, colour copies and the folders. We’ve been enjoying all of that part.

F01

And for me to have my guide, my facilitator guide so I’m sitting there with that one guide constantly and making notes and thinking about it, um, I like that as well, that’s a big help.

F02

Challenges of delivering the new course were also discussed. Difference in delivery style (i.e. from ‘classroom’ to a more interactive style) and running all sessions with both parents and children present were raised by one facilitator as big challenges:

Wow, massively challenging because it was very different, the course previously was only involving the parents and it was a very much classroom-based type thing, ‘you listen to me, this is what I would like you to do’ kind of thing. We met the children only at the beginning and at the end, so we didn’t really have to interact with the children as much, um, we only took their weight and height, you know their weights and measures at the beginning and the end, we were trying basically to persuade the parents that this is how they should be adapting their lifestyle to suit their children and to improve the health of their children, but it was very much more weight focused as well, so we had to think of a way to approach the subject because they were there because their children were overweight and that was always there. So the focus I think, and the delivery was very different, so when this course came along it was a lot more involved on our part and because the children were going to be there . . . the big difference is that the method of delivering it was going to have to be very different, so that I liked, um, and then delivering it I enjoyed.

F02

Saturday programmes

One of the adaptations of the new programme was more availability of programmes on a Saturday. With the standard programme, 25% of sessions were delivered on a Saturday, but with the adapted programme this proportion was increased to 50%. Both facilitators recognised that this had a positive impact on the success of the adapted programmes, as they believed that it enabled the parents to be more relaxed, outside the pressures of the working week, and allowed them to bring other family members along and, therefore, to embed the behaviour change messages more firmly into the family:

Families are, are very relaxed about Saturdays and, and I would say that they have been very successful . . . I think it’s the same as any of us though ‘cause on a weekday I just, on my working days oh God, I can’t take any extra on, you know. So I can see that for, for some families although they’re still doing it they might be quite stretched and then quite stressed out by the time they’re there, they’re not really concentrating. So I don’t know . . . they’re just, you know, a bit more relaxed and they’re probably just in a better mind frame, erm, to concentrate on something, something that’s gonna benefit their family.

F01

It does make a massive difference because the family can come, the whole family can come, whereas during the week you know even some adults find it difficult to take that hour and a half you know they’re working or you know they’re at home but they’ve got other you know commitments . . . but an hour or so on a Saturday morning before the weekend starts if they’re motivated to come to it, which most of them are it has to be said, it seems like the obvious time to do it and you do get, you get siblings along and the messages apply to them just as much as it applies to the person who’s been nominated to come.

F02

Children in attendance

A key adaptation was the presence of parents and children at all programme sessions (children attended only the first and last sessions of the standard programme). The facilitators were clear that this had a positive impact on the programme for a number of reasons. From a delivery perspective, they felt that the delivery needed to focus on engaging the children to keep them interested, and this would have a positive impact by removing the spotlight from parents and lessening the perception that their parenting was being criticised. They also felt that the children motivated the parents to keep attending the programme sessions, and they valued the opportunity to witness interactions between parents and children, as this helped to shape the support they gave the families:

. . . the children were going to be there, and if you can engage the children then you stand a lot more chance of engaging the parents because sometimes it’s very difficult to persuade an adult not that they’re doing something wrong but you’re always treading that line between you’re kind of not being a very good parent are you?. . . but when the children are there you can approach it in a very different way, so when we were given this course it was obvious that that was going to be, the big difference is that the method of delivering it was going to have to be very different, so that I liked.

F02

The children drive it. If the children can drive it, ‘I want to go, I want to go, I want to go’ then the parents will bring them, they just will whereas if the parent is going ‘do you know, I can’t be bothered to go’ they just won’t but if the child is there going ‘you, I want to go’ so having the children there I think it has made the whole course has made a difference to attendance I think, definitely.

F02

Erm, and also as a, get, having the kids involved was such a big plus for us because like I said, there were lots of reasons why we’re, it was, you know, it was good to see them with their parent and what their relationship was like and act with them. We’re there, you’d act, you’d know whether they’re doing the, the targets or not which was hilarious because you’d just see in their faces they weren’t.

F01

However, the facilitators identified that having younger children in the group was a big challenge. They felt that the content of the programme was beyond the comprehension of 4- and 5-year-old children and this sometimes resulted in them losing interest and disrupting the session:

We had very young children there so I think we need to think about it in terms of the age of the children and age appropriateness, which I don’t think we thought about at all, any of us, when you’ve got 4- and 5-year-olds there they’re not interested because they’re 4 and 5, whereas when they’re kind of 6 and 7 they can sit and talk to you and listen.

F02

In actual fact, talking age of children, some of the age groups we did realise . . . that we found that the 5-year-olds were losing interest very quickly . . . It was that the very young ones were so in, in reflection to what I’ve just said, because some of the content was still quite, I would say, I would say quite hard for them to understand when we’re talking about things like carbohydrates and things for a 5-year-old that’s just gonna go straight past them. They would lose interest but it became sort of a bit of challenging.

F01

Programme content

Both facilitators expressed concerns about the ‘healthy eating’ session (week 2). There was a feeling that all the nutrition messages were packed into this session, whereas with the standard programme this content was spread throughout all sessions. This session had been revised so that the content was reduced but the facilitators remained concerned about its delivery. One facilitator highlighted that trying to give the planned amount of information to the participants in this session created a conflict with the programme’s ethos of listening to, and being responsive to, participants:

. . . but we only had about an hour to deliver what we were previously delivering in 6 weeks, and it’s a lot of information for anyone to take in. Even as a nutrition professional there was a lot of information to kind of get in for an hour so to deliver it to parents, and for them to go away. It was kind of they were reeling from all the information that we were trying to give them.

F02

Erm, but that was the only thing that I really struggled with was week 2 to actually get that, all that information across and it didn’t really, then it kind of went against what we were trying to do, which was giving them a chance to sort of interact with us, because there was so much.

F01

One facilitator felt that the programme was imbalanced in terms of having too great a focus on physical activity and not enough of a focus on nutrition. However, this was in contrast to the views expressed by the parents and children:

I think that’s my biggest frustration about the course itself is that we’ve moved too far in down the road to saying physical activity is key, and it is key but they need to go hand in hand and we are losing the practical food tips, so that’s my frustration I think, um, with the course because overall I love it and I much prefer delivering this one than I did the previous one which was a lot more stilted and a lot more formal but the balance has shifted . . . we should talk about the food again and the physical activity and try and marry them both together.

F02

The same facilitator also expressed her frustration at the shift in focus of the adapted programme away from weight management and towards healthy behaviours. In contrast to the findings from the qualitative study in phase I, she felt that a focus on weight was necessary and led to better outcomes in terms of weight loss:

So [on the standard programme] we were giving them practical [advice] – look at this, did you realise, no I didn’t, I’m going to change it for that, and it was like a peg, they could grab onto that one and do something about it whereas [on the adapted programme] we always veered away from the words weight, overweight, and it was healthy lifestyle, which is fine but the results at the end anecdotally I don’t think were as good in that regard.

F02

Although they preferred the adapted programme overall, both facilitators clearly identified aspects of the standard programme that they valued highly but that had been omitted in the nutrition content in week 2 of the adapted programme. In particular, the use of visual props, such as showing the actual amount of sugar in a fizzy drink, was felt to be of great value in delivering key messages. In addition, one facilitator felt that the messages on how to implement changes were less clear to participants than in the standard programme, and some of the more practical tips had been lost in the adapted programme:

Everybody is astounded when they see those kinds of sugar, it just, something just drops, the penny drops even though they think they know until they actually see it physically and I think we missed that massively and the plate, the portion plate, not the Eatwell plate but there’s a portion plate, because when you look at the size of the plate as well and I think visually, props-wise, we needed to incorporate more of that stuff . . . The parents all know cans of coke have got sugar in them, but until you pick up the sugar bag and put it alongside it, that’s when the shock registers as to exactly how much there is.

F02

The only thing that I would say is that when it came to sort of the nutrition side of things, I still found that things were a little bit vague . . . when we talk about carbohydrates and things, I still think they needed a little bit more direction as to how, you know, like how many portions they should be having or just that staying a little bit clinical, erm, with what we’re expecting them to do, which we didn’t really, in the new programme we didn’t really go into, which is the only thing that I was a bit, er, sceptical about.

F01

Both facilitators reported that many parents returned to discussing nutrition and healthy eating in the third session when their children were not present (‘making changes’, week 3). One facilitator found this very helpful as the parents themselves were bringing up points from the previous session and it gave her an opportunity to tie in healthy eating messages with changing behaviours. In contrast, the other facilitator felt that this was a sign that the messages were not covered in enough detail and that parents were frustrated:

. . . and they would say [in week 3], you know, ‘Oh’, you know, ‘This is the issue that we’re having with food again’, so they’d bring that back up and it was kind of nice because although we were, we were discussing and delivering behaviour change, it kind of brought in stuff from the previous session and an opportunity for them to ask questions without their children being there . . . it was nice for them because they sort of felt like there was a bit of a break, you know, a breakout for them where they’d actually have a chance to, to ask us, you know, ‘This is what we’re struggling with’, or, you know, not necessarily just behaviour, just in general all their habits and how to break them.

F01

I have found in my behaviour, the behaviour session [week 3] when the children go away and I’ve got the parents there we tend to spend the first half of that session talking about food, portion size, tell me about how many meals they should be having a day and it’s kind of well we did cover that last week but they’re frustrated that we didn’t cover it in enough detail or give them something like, I’m going to show you my hand, this is the size of the plate, you know the fist, any kind of practical tips as to how much they should eat, when they should be serving their children.

F02

Programme website

The facilitators had differing opinions on the value of the website. One was very positive about the website as a resource for families, whereas the other felt that there were barriers to its use among the programme participants, although she acknowledged that it was a good resource for older children who may have more information technology skills than their parents:

Apart from the fact it had my face in I loved it, no I think it’s great because we’d always been asking for a resource that we could give them um anyway, so I think it’s a great idea and I do like it, and I think it’s easy to get around, um, because the courses are so short I think sometimes they’re left hanging and go well, what do we do without seeing you every week now? And to be able to say to them you’ve got your website, you’ve got my number, both those things, everything is there and if you can’t find the answer there then you can phone us and we can support you because that’s you know that’s what they want, they want some support, and having that is brilliant.

F02

Erm, I would say that some of them were a little bit sort of not, erm, what’s the word, sort of computer whizz, so some of the parents like, well who had language barriers and things wouldn’t really, I would say, go onto a website . . . But some of the kids that were, I would say, at an age where they understood ‘cause kids, you know, kids are computer whizzes so they knew what they were doing, they, they would say they’ve been on, erm, some of them had looked at recipes.

F01

Overall experiences

In general, parents and children reported attending the programme as a positive experience and felt that it had encouraged them to make behavioural changes. Several participants discussed the wider impact that the programme had within the family, with many reporting behavioural changes that had occurred in other family members. These wider impacts were not confined to families who completed the programme, with some participants who had only partially attended reporting that there were behavioural changes within the family as a result of attending sessions:

. . . the whole thing it was delivered so softly it was just about making sensible choices, informed choices, you know, and I think that we got all the tools that we needed to do that, you know, we were told everything and the way it was delivered was superb, I can’t say that enough it was just from start to finish it was a really good course. Er, and yeah we’ve continued doing it and we’ve made changes and we’re continuing to make changes.

P2148, father, black, completer

All I can say is it was a brilliant experience for my daughter because she’s made a major change in her life and I think as she grows older she will realise, you know, how to keep on going that was instead of going the other way she was doing, that’s the only other thing I can really say.

P2079, mother, Pakistani, non-completer

. . . it was really good, it helped a lot, erm . . . I enjoyed going to it because it was fun, yeah.

C2148, child, mixed/other ethnicity, completer

. . . but I think whatever we learnt, we will actually stick to it erm, in our family, her dad is one that he loves his food and drink, so changing him was quite hard, but even like, if he has a choice with a meal he might actually chose a water instead of the fizzy drink now, whereas before that wouldn’t have even been an option . . . I think you know, even whilst I was doing the course I was mostly focusing on my daughter, but after the course I thought I don’t actually have any physical activity implemented on myself so I’ve started doing my walks, going to the gym, doing a bit of aerobics.

P2025, mother, Pakistani, completer

I think all of it was because I could see her weight and I could see what I could do as a parent to help her and all my family. And my husband made a few changes in his diet as well, like he picked up that, because he used to eat unhealthy and now he’s eating healthily and he’s going to the gym as well, so I think so it has worked for us.

P2079, mother, Pakistani, non-completer

Er, I’ve sort of, er, changed portion size as well for the 2 year old and I haven’t changed the size of the plates yet, but portion size I’ve changed, er, fruit and vegetables, they eat a lot more fruit, they’ve always even before we started the programme they really love their fruit but the vegetables with the two younger ones was a problem, but with [child name] he eats almost all vegetables.

P2124, mother, black, completer

Some parents felt that they already knew some of the information presented within the programme, but they acknowledged that they also acquired new knowledge:

They explained quite well, I mean what to eat and what should be avoided. Although I already knew about this but it is common when we attend such events we always learn some new information, so this helped me a lot.

P2017, mother, Pakistani, non-completer

But the stuff was pretty much a lot of stuff we’d already knew, you know, and we picked up and stuff already, so – but there was a – quite a few beneficial things, like stuff like, erm, for instance, erm, like the [brand name] jars, like we didn’t – we knew they had sugar but we didn’t know how much and stuff like that, and then the sugar stuff smart [application] and stuff like that.

P2112, mother Pakistani, completer

The group-based aspect of the course was generally well received by both parents and children. Parents valued the support they gained through sharing experiences with and learning from other parents, and children enjoyed the opportunity to make new friends:

It was nice to be around other people that had the same like issues with weight management stuff with their children, because the support was good, as in, you know, to be around other parents and, you know, just generally when you talk to the parents and stuff, you kind of like – it makes you realise that you’re not the only family with this issue and stuff, so the support helped and stuff.

P2112, mother, Pakistani, completer

It was brilliant because I’ve, good idea, because for me, it’s just I’m learning things and I learned through other parents as well, if I listen to them I get some ideas as well and they learned something from me as well.

P2079, mother, Pakistani, completer

OK, so let’s go through the things that you liked, so [child wrote] ‘the course helped me doing things which I enjoyed’, fantastic, so what do you mean around that, what did you enjoy?

The things that I enjoyed was like, I got to make new friends and everything.

C2091, child, Indian, completer

In line with the facilitators, parents found the session in which the children undertook activities separately (week 3) to be very beneficial, as it allowed more opportunity to develop relationships with other parents:

The week that [name of child] went off to do her stuff, I think you [talking to child] really enjoyed it. And it was quite a – it was quite useful as well – it was quite useful as well to have an opportunity to talk about things while [name of child] was busy doing something else.

P2115a, mother, white, completer

Programme timing

Programmes delivered on Saturdays were generally well received. One parent expressed concern at taking her child out of school on a weekday during an important school year and so chose a programme on a Saturday that was much further away. Some parents and children reported that a 9.00 a.m. start on a Saturday morning was challenging for them:

It was [the Saturday programme], oh gosh it was at [place name] which is two bus rides away so . . .

Oh it was quite a way then.

The other one was in, er, [place name] but because it was on, er, Tuesday afternoon at 1 o’clock I didn’t want him to go to that because he’d miss 2 hours, not even 2 hours, half a day of school because he’d have to leave school early.

P2124, mother, black, completer

Fantastic. OK, so things you did not like. You [child wrote] ‘had to go early in the morning and it feels difficult’, was it a really early start?

We like started, like, I used to go there at 9 o’clock . . .

OK, was that on a Saturday . . .?

Yeah . . .

So that’s a bit early for a Saturday . . .

Yeah . . .

So you’d like it to be a bit later . . .

Like go at 10, 10 o’clock . . .

C2091, child, Indian, completer

Programme structure

Parents were mostly happy with the six 90-minute programme sessions delivered over 6 weeks. A minority of parents commented that they would prefer a different structure, either a more intensive programme with sessions close together (e.g. over the summer holidays) or a programme delivered over a longer time period:

Maybe that it was just once a week basically. Maybe, yeah. ‘Cause now that we’ve got a 6 week [school holiday] that could take place now and the children off – off school.

P2026, mother, Pakistani, completer

I think personally that there should be a programme for overweight children that they should be in touch with them regularly, rather than, you know, just a session – like a few sessions clustered together, or you – do you know what I mean? Like a longer time period to kind of lengthen that.

P2112, mother, Pakistani, completer

Barriers to programme attendance

Parents who did not complete the programme generally recalled logistical reasons for not attending. This was consistent with the findings in the phase I qualitative study. However, one parent felt that his child was uncomfortable with being identified as overweight and that he did not identify himself as being the same as the other children who were attending the group:

I wanted to join again but my car broke down. However, they said if you want to come please let us know, though I wanted to go but I had this issue so I said I will try to come . . . In the beginning I attended two sessions and then one more, but then I could not go. I wanted to go with my friend but I could not go in the last three sessions.

P2017, mother, Pakistani, non-completer

Because of getting from school to go it was – and because going to college and stuff, it’s kind of – was kind of impossible to attend every session.

P2055, mother, black, non-completer

. . . from first impression I find all of them they’re fat kids and this kind of – this, erm, first impression, it can affect him. He thought, ‘Am I one of them? I’m not fat. I’m a sportsman’. So from that side I think that can affect him saying, ‘No, I’m not the one to attend this kind of course.’

P2047, father, mixed/other ethnicity, non-completer

Children in attendance

The inclusion of children at all programme sessions was generally very well received. Parents valued the fact that children were directly hearing messages relating to healthy eating and physical activity from a professional, and some also felt that it provided an opportunity for them to start conversations around weight management with their child:

It was actually quite useful because most of the time children won’t listen to parents, but when they see a professional explaining they take on board. And I think it was actually tool for me to reach him, so it’s literally opened our communications between us so it was quite useful really.

P2092, mother, black, completer

. . . I thought you know, we might as well go for it and see what happens and when we did go, finally when they finished, I thought it really, really helped, I think that bit of encouragement from somebody else rather than the mum saying to the child, I think it really helps.

P2025, mother, Pakistani, completer

Parents also identified some difficulties with having children present at the sessions. In line with the facilitators’ views, some parents felt that the wide age range of children presented a difficulty, with younger children becoming disengaged and older children becoming bored:

I definitely think, it probably didn’t have the same, er, the same accessibility or the same outcome with the younger children, I felt that they were you know they weren’t engaged in it, they were more playing with toys and all of that, so it didn’t really benefit them too much. And as a result because they were getting into mischief and the parents were being drawn away from it and possibly missing key points, er, but yeah for the older children, I’d probably say 9 upwards they were fully engaged and they were listening to what was going on, you know, and they were taking it in. I don’t think it was much use for the younger, if anything it was more of a hindrance.

P2148, father, black, completer

Erm, I think a little bit, because [child’s name] was one of the, I’m not really sure if she was one of the eldest but she was a Year 6 child and she’s quite bright anyway so a little bit of it was too basic for her, so she found that, like occasionally you know once the main part of it, she found it a little bit boring so maybe if you were to do it again, split it up into the age groups.

P2025, mother, Pakistani, completer

They just got a bit bored, didn’t they, after it? It’s quite – it was about an hour and a half, and I think it was just too long for some of the little ones to sit and listen.

P2115a, mother, white, completer

Pitching the sessions at the right level to engage both the children and the parents was also identified as a challenge, particularly around more complex concepts such as food labelling. This activity in particular evoked differing responses from participants, ranging from those who found it challenging but learned from it to those who felt that it was too complex for the children to grasp:

To be honest with you we both learned, it’s whatever applicable to the children was also applicable to the parent as well. And I think one of the useful things which I never really pay attention initially was the food labelling, was that fat and how many grams salt, it’s not something I normally pay attention, I just grab them.

P2092, mother, black, completer

I think she didn’t really pick on it that much, for her if you put a package in front of her it’s still going to be a package. She did sort of understand that if she had too much it’s bad for her, that’s it, but I think it was more for adults.

P2079, mother, Pakistani, non-completer

Erm, it was quite fun at first. Err, it was quite fun altogether because we had to go round the room and we had to find the different foods. Then you had to find out how much they were labelled in, err how much sugar and fats are there in there.

C2025, child, Pakistani, completer

Um, I didn’t like the food labelling activity because you didn’t get to write the um, you had to quickly write the words down and um, you had to like, you would get muddled up and things. And uh, you would get confused. But with the sheets I’ve got in my folder, I know which is a healthy snack and which is not.

C2063, child, Pakistani, completer

Physical and other activities

In contrast to the facilitators’ views, parents felt that there was still not enough focus on physical activity, despite the incorporation of physical activity into each session and a dedicated physical activity session for children. Children really enjoyed the physical activities, along with the food-making activity. Some parents and children reported that there was too much sitting and listening for children, despite the increased interactive content:

I think it was really good although I think they could have done a bit more in sort of 1 day, like if she went the next week they could have done a bit more, I think that would have been, now she’s picked up on it anyway she does exercise but I think if they increased that a little bit more . . .

A bit more activity?

Yeah a bit more activity, as well as the food and diet, but more activity as well.

P2079, mother Pakistani, non-completer

Yeah, but I thought there’d be more like activities for the kids and stuff, I think they only had activities on 1 day and the other time they had, that’s when they had to make snacks, so the rest of the time they were sitting there and [child’s name] would say, do we have to go because it’s so boring just sitting there.

P2124, mother, black, completer

Like, erm, when you got to do some exercise for only 1 week, and sitting down, that’s not much fun, it was supposed to be fun but it wasn’t that fun . . .

C2124, child, black, completer

Right, OK, for the second [sticky note] you’ve mentioned [child wrote] ‘I would like to do more active activities there’. So do you want to explain?

Well I would have liked to, um, in the course I would like to like be more active, like run around and stuff like, they’d only, I think on like the last or two lessons [hmm-hmm], I was there for the course and they were active and you were playing games and things.

C2063, child, Pakistani, completer

Some parents suggested that local community facilities could be used, such as the park or local leisure centre:

I think it was good, erm, I think at the time the weather didn’t really support us so we couldn’t really go out but, erm, if you were to do it again, maybe one of the sessions could have been at the park or at a leisure centre or something to actually, erm; they did go into the playground for a while, but if you were to do like a full session outside with the parents, maybe that would have helped, but we learnt that the children need, the amount of exercise they need each day which is quite a lot if you think about it.

P2025, mother, Pakistani, completer

You know, it was in the morning, weekend morning, was I think my son also plays with his friends, er, and I think if he can – you know, I’m thinking if they can – if they can do that the same activities in the park, the student with the kids always playing there, some kind of – some activities, they always, erm, start that kind of, erm, erm, er, activities in the park. So if they can move the place to the park maybe.

P2047, father, mixed/other ethnicity, non-completer

Programme website

All participants were asked about their use of the website. Only one parent and some of the children reported having used the website; however, it is possible that there was some confusion between the programme website, developed as part of the adapted intervention, and the nationally available Change4Life website (https://registration.change4life.co.uk; accessed 20 April 2017). This suggests that this may have been a less useful aspect of the programme and possibly signposting to existing online resources, such as Change4Life, may be a more cost-effective option:

Yes, but not as much as I should have if I’m honest, I used it three or four times and we did use it, er, we did use it every now and again just to look at food, the sugar content and the fat content because of the items on the site because some of the – some of the cards and things like that.

P2148, father, black, completer

Data collection in the participant’s home

A number of difficulties were experienced with the data collection visits to the participant’s home. The home visit appointments were made by telephone a few days in advance, with a follow-up confirmation letter and a reminder text or telephone call on the day of the appointment. Despite this, on several occasions the families were not at home when the researcher arrived. Some participants gave reasons (e.g. unplanned hospital trips, unexpected school commitments); others did not give an explanation. It was possible to rearrange some of these data collection appointments, but some families were lost to follow-up as repeated attempts to contact the family and rearrange the visit failed.

Initially, data collection home visits were planned to be undertaken by one researcher and a lone-working policy was implemented. Following the first few visits, concerns were raised by researchers, as many appointments were during hours of darkness and often they had to park their car some distance from the home and walk with heavy equipment in unfamiliar areas. Therefore, it was agreed that first visits to a home should be attended by two researchers and that a risk assessment should be undertaken for lone researchers to make the subsequent visits.

Participant burden

At the start of data collection, the baseline home visits lasted a median length of 60 minutes, ranging from 40 to 90 minutes. In some cases this was too long, with participants becoming fatigued before data collection was completed. Researchers noted early on that the number of questionnaire items was too high for the adult participants. In response to this, the data collection process was modified in January 2016. The questionnaire booklet was divided into two. One contained core data questions (sociodemographic information, Children’s Dietary Questionnaire, FNPA questionnaire) and was completed at the appointment and the other (containing questions on parenting style, parental self-efficacy and parental feeding practices) could be completed by parents at the measurement appointment, or at a later date, and returned to the research team in a Freepost envelope.

For non-English-speaking participants, community researchers (or, when necessary, accompanying interpreters) translated all the questionnaires. Therefore, these participants did not have the option of completing the second questionnaire booklet at a later time. The data collection appointments took even longer for these families to allow for translation time and for all questionnaires to be completed. This remained an unresolved issue in the study.

Concealment of study arm allocation from researchers undertaking data collection

Programme allocation was unknown to the study team at the time of baseline measurements. However, once participants had started a programme, it became apparent to the study team which arm they were in through conversation with the participants and the presence of the programme materials within the home. This was less of a problem with the community researchers, as they were unaware of the differences between the intervention and comparator programmes. In a future trial, study arm could be concealed from the researchers undertaking the measurements if they are separate from the researchers who are co-ordinating the study and undertaking process evaluation of the intervention.

Other issues

Ramadan is a period of fasting during daylight hours that is observed by many Muslim families, and in 2016 it was within the planned T1 measurement time period. It became clear during the study that the participating Muslim families did not want a data collection appointment during Ramadan. Therefore, we delayed the appointments with these families until after the end of this period.

Anthropometric measurements: children

All children consented to height and weight measurements being taken and, therefore, a BMI z-score was calculated for all children. At each time point, two children had invalid body fat percentage measurements (e.g. the child did not want to remove their socks); therefore, the number of children with body fat percentage z-scores is marginally lower. Of the anthropometric measurements, waist circumference had the lowest compliance at each time point, with 15–28% of children declining this measurement. Children were asked to raise their clothing to access the waist; however, if they refused, an option was given to take the waist measure over thin clothing. When utilised, this was noted on the case report form (T0, n = 4; T1, n = 2; T2, n = 1).

Questionnaires

All child-completed questionnaires (the PedsQL, the Figure Rating Scale and CHU-9D) were completed at the home visit appointment and had good completion rates [ranging from 87% (T2, PedsQL score) to 100% (T0, CHU-9D score)].

Parent-completed questionnaires were split between those that were completed at the home visit appointment (the Children’s Dietary Questionnaire and the FNPA) and those for which parents had the option to complete after the home visit and return by post (from January 2016; the authoritative dimension of the Parenting Styles and Dimensions Questionnaire, Parental Self-efficacy scale and various subscales of the CFPQ). Completion rates for those questionnaires completed at a home visit ranged from moderate (62%, T1, FNPA score) to good (97%, T2, Children’s Dietary Questionnaire: fruit and vegetables score). However, those questionnaires that could be completed later and returned by post had substantially lower completion rates, ranging from poor (43%, T2, the authoritative parenting score) to moderate (67%, T0, parental self-efficacy score).

Physical activity measurements

Two types of accelerometer were tested: the wrist-worn GENEActiv and the hip-worn ActiGraph. The aim of using both accelerometer types in this feasibility study was to determine whether or not there was a difference in compliance between the two monitor types. GENEActiv monitors are less established in the literature than the hip-worn ActiGraphs; therefore, it was planned to use the GENEActiv monitors on approximately 75% of participants. Table 13 highlights the difference between the monitor types at each time point. At T0, the return rate and proportion of children who wore a monitor for at least 1 valid day (> 10 hours) were similar between monitors. However, at T1 and T2, both were lower for the hip-worn ActiGraph. For those who wore a monitor, the number of valid days of wear time recorded was similar between monitor types (Figure 9).

FIGURE 9.

Physical activity monitor: median valid days of wear at each time point.

Anthropometric measurements: parents and other family members

The purpose of undertaking anthropometric measurements (height, weight and percentage of body fat) with parents and other family members was to assess the feasibility of collecting data that would enable evaluation of the impact that the intervention had on the wider family. The collection of these data proved problematic. At baseline (T0), of the 75 families who had a data collection home visit, 64 (85%) had at least one other family member and 37 (49%) had at least two family members who consented to measurements. These proportions reduced to 78% and 34% for T1 and 60% and 28% for T2, respectively. A major issue was that the family members who consented to be measured at each time point were often not the same, that is, one sibling was measured at T0 and another sibling was measured at T1, etc. The implication of this is that it would not be possible to use these data to evaluate the impact that the intervention had on the BMI or percentage of body fat of other family members, as the data are so incomplete.

Study design

The feasibility study was designed as a cluster RCT to enable assessment of the proportion of families that completed the adapted and the standard programmes in the two study arms. We were able to execute this study design within the existing structure of the children’s weight management service. The cluster design enabled participants to attend the most convenient programme for them and was appropriate for a trial in which both the intervention and the comparator are group-based programmes. However, in a future trial to evaluate clinical effectiveness, consideration needs to be given to the comparator arm. The difference in effect size between two programmes that one may expect to see may preclude undertaking such a trial because the sample size would need to be very large. A more feasible approach to a future clinical effectiveness evaluation would involve having a comparator arm that has no active intervention programme. In this scenario, the required study design would be a trial randomised at the individual level. Therefore, using the data generated by this feasibility study, we have undertaken a sample size calculation for a future individually randomised controlled trial that compares the adapted group-based programme with no intervention. One parameter required for this calculation, which we have not been able to estimate in the feasibility study, is the likely difference in effect between a group receiving the intervention and a group with no intervention. We have, therefore, drawn on available literature to determine this parameter. We selected a mean difference in BMI z-score between study arms of 0.15 because, although there are currently no data to support a clinically meaningful threshold for change in BMI z-score,104 significant improvements in a range of cardiovascular disease markers have been reported with this level of BMI z-score reduction. 105

To test a mean difference in BMI z-score of 0.15 in a study population with a BMI z-score standard deviation of 0.6 (as reported in this study) at 90% power and 5% significance, allowing for a correlation between pre- and post-intervention measurements of 0.7 (which is a conservative estimate), 169 participants per study arm would be required. However, the proposed trial, although individually randomised in design, would have clustering in the intervention arm because of the group-based nature of the intervention programme and, therefore, given the findings of this study, attrition also needs to be taken into account in the sample size calculation. Assuming that the programme is delivered to groups of 10 and allowing for 30% attrition, the expected cluster size after attrition would be 7. Therefore, assuming an ICC of 0.03 (as estimated in this study), the sample size in the intervention arm would be 199 [= 169 × 1.18 (= 1 + 6 × 0.03)]. This equates to approximately 199 participants being randomly allocated to the intervention arm across 28 (= 199/7) programme groups and 199 participants being randomly allocated to a control arm.

Participant recruitment and follow-up

We achieved our participant recruitment target of 80 in this study. We did not expect difficulties in recruitment as we were recruiting families that had already agreed to attend a children’s weight management programme. However, the process of recruitment proved problematic for a number of reasons and resulted in difficulties in undertaking baseline assessments with families before they started a programme. In a future trial, it would be necessary to plan carefully with all partners involved in participant recruitment to ensure that there is enough time to gain consent and undertake baseline assessments before the start of the intervention programme. If an individually randomised design was adopted, then randomisation of participants would need to be undertaken after baseline assessments and before the participants start a programme.

Participant attrition was a major issue, with one-third of participants being unable to be followed up at the 6-month time point. The majority of these were lost to follow-up rather than having actively withdrawn from the study, despite multiple attempts to contact them by telephone and letter. The level of attrition seen in this study is within the range of attrition seen in other children’s weight management intervention studies. The Cochrane review12 of 64 studies reported that participant drop out at 6 months ranged from 1% to 42%, with only 31 studies reporting a follow-up of > 80%. The high attrition seen in this study may, in part, be explained by the characteristics of the study population: Birmingham has high levels of population turnover. 106

Attrition poses a major challenge for a future trial to evaluate intervention clinical effectiveness. In this feasibility study, as well as there being a high level of attrition overall, there were differential levels of attrition in the two study arms (29% in the intervention arm vs. 52% in the comparator arm). This makes the interpretation of outcome comparisons between the two arms more complex and necessitates data imputation, as demonstrated in our exploratory outcome analyses. Differential attrition across study arms has been less commonly reported in other studies. 12 There are no obvious solutions to the problem of attrition. We designed our data collection processes to minimise loss to follow-up by offering appointments in the participant’s home, which has been shown to be an effective approach to reduce attrition;107 thus, it was disappointing to retain only two-thirds of the participants until the end of the study. In future research, we would recommend requesting as many contact details as possible, including all telephone numbers and postal and e-mail addresses. Rewards for participants at the final follow-up point should also be considered. In addition, the sample size calculation of a future trial should take into account a significant level of attrition.

Outcome data collection

Overall, the collection of outcome data worked well. The home visits appeared to be acceptable to participants, and they were feasible to undertake. However, the visits were resource intensive, with a great deal of staff time spent travelling to participants’ homes and there being a necessity for two researchers on the first visit. This is a consideration in the design of a future trial.

One issue that arose with the collection of outcome data was the difficulty in concealing the study arm that the participants were allocated to from the researchers undertaking the assessment visits. At baseline, this was in part because some participants had already commenced a weight management programme before the data collection visit took place. In a future trial of similar design to this feasibility study, separation of the research staff undertaking the outcome measures and the core research team responsible for the delivery of the study overall would help in blinding those undertaking the measures. However, in a trial comparing a programme with no intervention, blinding of staff undertaking measurements at follow-up could be challenging.

The feasibility study was planned to enable us to explore the feasibility of collection of a wide range of outcome data. It became clear during the study that the number of questionnaire instruments that we were requiring parents to complete was too much of a burden. In general, home visits lasting for more than 1 hour became wearisome for the families and the researchers. In response to this, we prioritised certain questionnaire instruments to be completed at the visit and asked parents to complete the others at a later time and post them back to the research team. This significantly affected data completeness, with only 43–58% of participants completing the second group of questionnaires at the follow-up time points. The other issue with splitting the collection of questionnaire data in this way was that it did not work for non-English-speaking participants. In these cases, the researchers either stayed to complete all the questionnaires or, if the participant became too fatigued, they left the second group of questionnaires blank. There is also the possibility that the heavy burden on participants at the data collection visits contributed to the high attrition seen in the study. Thus, in a future trial it would be important to consider carefully which outcome data are essential and to resist the temptation to measure too many outcomes.

Overall, sociodemographic and anthropometric data were relatively complete, as were the questionnaire measures that were directly administered to the child participants. Apart from the FNPA questionnaire, the parent questionnaires that were administered during the home visit were relatively well completed. In a future full-scale trial, we would recommend the use of BMI z-score as the primary outcome, given the completeness of data collection; however, it would be important to include other anthropometric measures as secondary outcomes, given the limitations of BMI as a measure of adiposity.

The anthropometric measurements with parents and other family members proved particularly problematic. The number of family members agreeing to be measured reduced over the three time points, and often those agreeing at each time point were different family members. Collection of family data in a future trial would need careful planning with prior agreement at the outset over which family members will be present to be measured at each data collection time point. This would be extremely logistically challenging.

Process evaluation methods

The implementation of the adapted programme was directly observed by researchers, who attended all programme sessions and also observed delivery by both facilitators. In addition, there was contemporaneous feedback from the facilitators on their reflection on delivering the session and how it was received by the participants. We also undertook a series of interviews with facilitators and participants. In this study, these methods were used primarily to assess the feasibility of delivering the adapted programme and how acceptable it was to the participants, as well as enabling refinement of aspects of the intervention during the study intervention period. However, these methods also enabled the collection of key process evaluation data that would be required to assist in the interpretation of the evaluation of outcomes in a future trial. In line with the UK’s Medical Research Council guidance on the process evaluation of complex interventions,108 we clearly articulated the causal assumptions underlying the intervention programme in phase I of this study and have collected data that enable evaluation of intervention fidelity, the degree of tailoring, participant responsiveness to the various elements of the intervention programme and the influence of context on both delivery and participant response. The experience of collecting these process data, together with the previous process evaluation experience of the research team,109 will inform the development of detailed tools to assist in process evaluation in a future trial, such as observation checklists and standardised facilitator feedback forms.

Economic evaluation methods

The economic component of the study aimed to design processes for, and capture data on, the costs and outcomes associated with the intervention and comparator programmes to inform the methods for a future economic evaluation alongside a definitive trial. On the whole, processes were successfully put in place to measure the costs associated with the adapted programme. Data were successfully collected on the costs associated with producing the adapted programme materials. However, some challenges were also encountered. In particular, difficulties were encountered in terms of capturing data on resource use for the comparator programmes. As this represented ‘routine practice’ for staff delivering the programmes, it was difficult to separate out the costs associated with conducting the standard programme from other day-to-day activities. In a future trial, if the same design were adopted, we would recommend having separate processes for capturing the costs associated with producing materials for comparator programmes.

As part of the study, we aimed to collect data on the costs borne by families in attending the weight management programme. These data were collected via a questionnaire distributed at the end of the programmes. Problems were incurred by collecting data in this way. Very few questionnaires were returned by those attending the comparator programmes and the questionnaire was completed by all programme participants at the final session, rather than by only those who had participated in the CHANGE study. We would recommend that, in a future trial, these data are collected alongside the outcome data rather than separately at the end of the programme.

The core outcome data that could be used in a future economic evaluation were collected successfully (see Outcome data collection). This would permit different types of economic evaluation to be conducted in a future definitive trial. First, a cost-effectiveness analysis could be conducted, using the primary clinical outcomes included in the trial, for example estimation of the cost per mean change in BMI z-score. In addition, collection of CHU-9D data would allow a cost–utility analysis to be undertaken as recommended by NICE. However, as discussed (see Outcome data collection), it was not feasible to collect the data to capture the impact that the intervention had on the wider family (anthropometric measurements on parents and other family members). The design of the economic evaluation alongside a future trial would adopt two approaches: a within-trial analysis that would estimate the cost-effectiveness using data generated by only the trial on the basis of an intention-to treat principle and, if appropriate, a longer-term model-based economic evaluation extrapolating both the costs and outcomes over a lifetime. The model-based economic evaluation would need to follow standard guidelines for decision-analytic modelling by adequately capturing the uncertainty with long-term intervention effects, future costs and outcomes linked to disease associated with being overweight and structural uncertainty within the model.

Exploratory analyses of intervention effect on participant outcomes

This feasibility study was not designed to assess intervention clinical effectiveness; however, we undertook exploratory analyses of our outcome data. Although we did show a favourable direction of intervention clinical effect at the end of the programme and at 6 months, the effect size was small. Given the continuing refinement of the intervention programme during its delivery, the high and differential study attrition and the lack of ‘true’ baseline data for some participants (as some T0 measurements were taken after the start of the programme), we cannot draw any conclusions from these analyses, other than that there is a signal that the adapted programme results in some reduction in BMI z-scores and other anthropometric measures.