Healthy Childcare Centre of the Future
Conditions: Health and Wellbeing of Primary School-aged Children
Sponsor: Maastricht University Medical Center

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Study Protocol Health Childcare Centre of the Future 
 
STUDY DATA 
Title 
Healthy Childcare Centre of the Future 
Acronym 
HCCF 
NCT number 
NCT04193410 
Date protocol 
04-02-2020 
Members research team  
Data 
 
Role  
 
 
1 
Marla Hahnraths, PhD student 
Maastricht University, department 
of Family Medicine 
Principal investigator 
2 
Prof. Onno van Schayck  Maastricht 
University, department of Family 
Medicine 
Project leader 
3 
Dr. Maartje Willeboordse 
Maastricht University, department 
of Family Medicine 
Coordinating investigator 
Principal investigator 
E-mail address: 
mth.hahnraths@maastrichtuniversity.nl 
Phone number: +31433882091 
Contact person 
E-mail address: 
mth.hahnraths@maastrichtuniversity.nl 
Phone number: +31433882091 
 
 
 

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TABLE OF CONTENTS 
 
Summary 
3 
1. 
Introduction 
3 
1.1 
Research questions 
6 
2. 
Methods 
7 
2.1 
Study procedure/study design 
7 
2.2 
Recruitment and selection of participants 
8 
2.3 
Data collection 
10 
2.4 
Data analyses 
11 
2.5 
Data management 
12 
3. 
Ethical considerations 
14 
3.3 
Burden, risk and incentives for participants 
14 
3.4 
Participants’ consent 
14 
4. 
Valorisation and publication 
15 
References 
16 
Appendices 
19 
Appendix I. Table Data Collection 
19 
 
 
 
 

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SUMMARY 
Rationale: From 2015-2020, the ‘Healthy Primary School of the Future’ intervention took place in 
Parkstad. The school environment of four primary schools changed. Two schools became ‘Healthy 
Primary Schools of the Future’; providing their students with a healthy lunch and structured physical 
activity (PA) sessions during lunch time breaks. Two other ‘Physical Activity Schools’ only 
implemented the structured PA sessions. METC Z previously decided that this study falls under non-
WMO guidelines (METC-Z no. 14-N-142).  Interim analyses showed promising effects of the 
intervention; at two-year-follow-up, the study showed a significant decrease in BMI z-score of 
children in the ‘Healthy Primary Schools of the Future’ as compared with children in control schools. 
Also, positive intervention effects on dietary and PA behaviours were observed. Following these 
promising results, childcare centres of educational board Prisma have expressed their interest in 
implementing changes fitting the ‘Healthy Primary School of the Future’ initiative. However, this is 
more complex than it seems to be, as budget to implement changes is lower than in the original 
trial, and all childcare centres have a unique context. Therefore, there is a need to investigate how 
‘Healthy Primary School of the Future’ can successfully be implemented in various, real-life school-
settings. It is hypothesised that to maximise implementation and sustainability, each childcare 
centre will need to put together a set of changes and interventions which fit the context and needs 
of all stakeholders involved (e.g., the school board, teachers, parents and children). 
Objective: The main objective is to study the implementation process of ‘Healthy Childcare Centre 
of the Future’ in different school-contexts and develop guidelines that can be used to facilitate 
widespread dissemination of the initiative. Secondary objectives include evaluating the effects of 
the ‘Healthy Childcare Centre of the Future’ on children’s BMI z-score, general health, dietary and 
PA behaviours and school well-being. To reach these objectives, a process evaluation, effect 
evaluation and cost-effectiveness evaluation will be executed. 
Study design: A non-randomised, non-controlled, observational study design. 
Study population: Children in study years four to six (at baseline) of twelve childcare centres located 
in Limburg. 
Main parameters/endpoints: The main study parameter of the effect evaluation is the change in 
absolute BMI z-score, which will be compared between the childcare centres that are categorised 
based on their degree of implementation (using categories based on the Diffusion of Innovations 
Theory). 
Methods: Data will be collected in the form of questionnaires (parents, children, 
teachers/pedagogical employees, directors), anthropometric measurements (children), interviews 
(teachers/pedagogical employees, directors), observations and analyses of minutes of meetings. 
Nature and extend of the burden and risks associated with participation: No intervention is 
allocated in this study other than activities planned by childcare centres in accordance with wishes 
and needs of childcare centre staff and parents. All outcome measures are non-invasive. The 
measurement protocol was designed while taking into account both a minimal burden for 
participants and a relevant scientific output for stakeholders (e.g., school board, teachers, 
parents/caregivers and children). Burden of participants is minimalised by incorporating most 
measurements in the regular school day.  
 
1. INTRODUCTION 
          In the Netherlands, the number of children suffering from overweight and obesity is 
increasing. In Peel en Maas, a region in the north of Limburg, 5.0% of 4.5-6 year-olds and 13.3% of 
9-11 year-olds suffered from overweight in 2016. For obesity, these percentages were 1.8% and 
2.0% respectively (1). The increasing prevalence of juvenile overweight and obesity is a public health 
concern, because they often have negative psychological and social consequences. Furthermore, 
they can increase the risk of developing certain non-communicable diseases (NCDs). The health risks 
associated with overweight and obesity also lead to an increase in health care costs, which puts a 
large economic burden on society (2–4). 

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          Important causes of the increasing prevalence of juvenile overweight and obesity are 
unhealthy dietary and physical activity (PA) habits. (WHO, 2017). Despite the health benefits 
associated with engaging in healthy lifestyle behaviours, the present habits of Dutch children show 
room for improvement. Currently, only 42% of children aged 4–9 years consume at least 150 grams 
of fruit per day; this percentage drops to 20% for 9–12 year-olds. The prevalence of vegetable intake 
shows similar percentages: 41% of 4–9 year-olds and 25% of 9–12 year-olds eat at least 150 grams 
of vegetables per day (CBS, RIVM, & The Netherlands Nutrition Centre, 2017). Looking at PA habits, 
only 17.1% of Dutch children aged 4-11 reach the advised daily norm of 60 minutes of moderate to 
vigorous PA and only 29.9% reach the Fitnorm (i.e., 20 min three days/week exhaustive PA) (7). 
These numbers underpin the importance of promoting healthy lifestyle habits in young children. 
Doing so could not only contribute to improvements in health but also to increased well-being (i.e., 
better concentration, increased feelings of happiness and satisfaction). 
          The school setting is the ideal environment to promote healthy lifestyle habits as:  
1) Health behaviours are learned at a young age, and healthy lifestyles learned early in life usually 
track into adulthood (8); 
2) There is strong evidence that healthy lifestyles are correlated with high academic achievements 
(Bass, Brown, Laurson, & Coleman, 2013; Edwards, Mauch, & Winkelman, 2011; Florence, Asbridge, 
& Veugelers, 2008; Van Dusen, Kelder, Kohl, Ranjit, & Perry, 2011); 
3) Children from all socio-economic classes will be reached; 
4) Directors, teachers, parents/caregivers and children are all involved in school-based communities, 
thereby involving not only children, but an entire community.  
          Worldwide, several high-quality health-promoting school initiatives have been evaluated 
(13,14). According to the WHO, a health-promoting school is one that constantly strengthens its 
capacity as a healthy setting for living, learning and working (15). In general, a school is considered 
health-promoting if interventions are given to reduce risk factors for NCDs (e.g., obesity, low PA 
levels, smoking, unhealthy nutrition), demonstrating active participation by the school and involving 
health-promoting activities in all or one or two of the following areas: 
(a) the school ethos and/or environment, such as school policy; 
(b) the school curriculum; 
(c) the family and/or community. 
          The majority of studies on healthy school environment focus on obesity prevention (16,17). 
Several meta-analyses and reviews showed that school-based projects can be successful, although 
effects are often modest (14,16–19). In a meta-analysis which included eighteen school-based RCT 
intervention studies in children, significant Body Mass Index (BMI) reductions of -0.076 (95% CI -
0.123 to -0.028, p<0.01) were found in intervention vs. control schools. However, results remain 
modest and several school-based interventions did not show reductions in BMI (20). The effects of 
health-promoting schools on lifestyle behaviours such as sedentary behaviour and dietary behaviour 
have frequently been studied as well. Saraf et al. showed that of all school-based interventions 
aimed at reducing risk factors associated with NCDs, 80% reported at least some evidence of a 
positive intervention effect (21). Examples of nutrition-related behaviours which can be improved 
with school-based interventions are consumption of high-fibre foods, healthier snacks, water, milk, 
fruit and vegetables (22). Also breakfast skipping, eating disorders, consumption of low-nutrient 
dense food, fatty and cream foods and sugar-sweetened beverages can be reduced in health-
promoting schools. In a meta-analysis of Evans et al. (2012), a significant average improvement of 
0.25 portions (95% CI: 0.06, 0.43 portions) of fruit and vegetable daily intake (fruit juice excluded) 
was found after implementation of school health interventions (23). Health-promoting schools are 
often accompanied with high exploitation costs for personnel, meals and logistics, which is a high 
barrier for implementation. However, health-promoting schools have the potential to be highly cost-
effective, as effects on several outcome parameters are expected. Prior studies already showed that 
school-based programmes may be more cost-effective in terms of quality of life and BMI when 
compared with other obesity prevention programmes (24,25).  

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          Despite the potential of school-based health interventions, they are often not integrated in 
the school system and are characterised by relatively low priority, a lack of coordination, and are 
often supply-driven, resulting in limited effects or effects that diminish in the long term (26,27). A 
major limitation of many school-based programmes is the lack of space in already full curricula, and 
time and financial concerns (20). In most of the school-based programmes, the physical and social 
environment is not adapted towards the ‘individual-level’ interventions. For example, Doak et al. 
highlight the difference between teaching children that they should be more active and eat more 
fruit and vegetables, and actually giving them the opportunity in terms of time, space and facilities 
to do so (28). Additionally, interventions are often not context-specific, although evidence suggests 
that there is a strong interaction between an intervention and the context in which it is being 
implemented (29). This means that what works in one school might not work in other schools, and 
therefore interventions should be adapted towards the specific context in which they are being 
implemented. 
          The above-mentioned flaws were taken into account in the development of ‘The Healthy 
Primary School of the Future’ (HPSF). HPSF is a Dutch initiative based on the Health Promoting 
School Framework (including e.g., a whole school approach, high involvement of parents/caregivers 
and partnerships). It acknowledges that implementation challenges can occur due to an interaction 
between the intervention and the context (30,31). In 2015, a quasi-experimental trial aiming to 
evaluate HPSF was initiated. This trial was previously registered on ClinicalTrials.gov (NCT02800616). 
It involved eight primary schools in the South of Limburg: four intervention schools and four control 
schools. Intervention schools introduced changes regarding the following key elements: 
- A healthy school lunch, which children consume together. The lunch is provided by school or an 
external caterer and its contents are in accordance with the guidelines from the Netherlands 
Nutrition Centre (at least 80% of the products being served are from the Wheel of Five); 
- A longer lunch break of at least one-and-a-half hour a day. In this way, there is more time for 
lunch (30 minutes), and PA and cultural activities (one hour); 
- Childcare staff guide the lunch break. Although volunteers are still welcome to help, the lunch 
break is mainly guided by professionals; 
- Sport and cultural coaches support childcare staff during the PA and cultural activities. External 
partners are active within the school environment; 
- Parents are actively involved from the start of the project. They share their views on further 
development of the project and they volunteer during lunch breaks. 
Two of the intervention schools implemented both a healthy school lunch and structured PA 
sessions during lunch break time (full HPSF schools). The other two intervention schools only 
implemented the structured PA sessions (partial HPSF schools). A detailed description of the study 
design, recruitment of participants and measurements can be found in Willeboordse et al. (32). 
Maastricht University is currently investigating the effects of HPSF on a broad range of effect 
measures (e.g., PA behaviour, BMI z-score, dietary behaviour). Although the project is still ongoing, 
interim analyses show promising effects. At two-year-follow-up, the study showed a significant 
decrease in BMI z-score of children in the HPSF schools as compared with children in control schools 
(33). Also, positive intervention effects on both dietary and PA behaviours were observed at two-
year-follow-up (34).   
          These promising effects have led to an increased interest among other primary schools to 
implement changes fitting the HPSF initiative. One of these interested parties is educational board 
Prisma. Prisma comprises several childcare centres in Peel en Maas, a region in the northern part of 
Limburg. Both childcare and primary education for children aged 0-12 years are located in these 
childcare centres, meaning that children are looked after by the same people prior, during and after 
school time. The goal of Prisma is to ensure a healthy development for all children. A means to 
achieve this goal is to implement changes fitting the HPSF initiative. However, this is more complex 
than it seems to be, as the budget to implement changes is lower than in the original HPSF trial, and 
all childcare centres have their own unique context. Therefore, there is a need to investigate how 
HPSF can successfully be implemented in various, real-life school-settings. To maximise 

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implementation and sustainability, each childcare centre will need to put together their own unique 
set of changes and interventions which fit the context and the needs of all stakeholders involved 
(e.g., the school board, teachers, parents and children). All changes will fall in one of the four 
categories: 
- Healthy and sustainable nutrition; 
- Sufficient physical activity; 
- Sufficient rest and relaxation; 
- Collaboration and social involvement 
        To aid childcare centres in the development and implementation process and to study 
programme effectiveness, the ‘Healthy Childcare Centre of the Future’ (HCCF) project was initiated 
in cooperation with a broad range of partners. The first part of this project was to assess the needs 
of various stakeholders involved in the project, which was done via questionnaires and interviews 
with several stakeholders. Thanks to this needs assessment, childcare centres now have a better 
idea of the views of important stakeholders such as parents, children and teachers. The second part 
of the project comprises the actual implementation of HCCF within the Prisma childcare centres. 
Maastricht University plays an important role in HCCF. Researchers will play an advisory role and 
study the implementation process of HCCF at the childcare centres. Additionally, researchers will 
study the project’s (cost-) effectiveness and compare its effects with the results from the HPSF quasi-
experimental trial. In this way, effectiveness and sustainability can be investigated and factors 
influencing implementation in various contexts can be identified and evaluated.  
 
Conclusion 
          This observational study will show how and to what degree HCCF can effectively and 
sustainably be adapted and implemented in various contexts. In addition, barriers and facilitators 
of implementation will be identified and based on these factors, guidelines for widespread 
implementation will be formulated. Furthermore, the study will investigate the effects of HCCF on 
a range of outcome parameters among which health, lifestyle behaviours, and cost-effectiveness. 
The results of the effect-evaluation will be linked to the results of the process evaluation to identify 
implementation factors that influence effectiveness. In addition, the effects will be compared with 
the effects observed in the HPSF quasi-experimental trial to investigate the potential of HCCF to be 
implemented in a real-world setting.  
1.1 Research questions 
Process evaluation: 
- How and to what degree is HCCF adapted and implemented in various school contexts (e.g., 
changes in school's practices, rules and regulations)?               
- What are barriers and facilitators of implementation of HCCF in various school contexts? 
- How can these barriers and facilitators be anticipated upon to facilitate maximum widespread 
implementation of HCCF? 
- What are the experiences of different stakeholders with HCCF? 
 
Effect evaluation: 
- Primary outcome: At two-year follow-up, is there a difference in absolute BMI z-score between 
children from different childcare centres, which have been categorised based on their level of 
innovativeness and implementation? 
- Secondary outcomes:  
 At two-year follow-up, is there a difference in waist/hip circumference between children 
from different childcare centres, which have been categorised based on their level of 
innovativeness and implementation? 
 At two-year follow-up, is there a difference in physical activity behaviours of children from 
different childcare centres, which have been categorised based on their level of 
innovativeness and implementation? 

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 At two-year follow-up, is there a difference in dietary behaviours of children from different 
childcare centres, which have been categorised based on their level of innovativeness and 
implementation? 
 At two-year follow-up, is there a difference in health markers of children from different 
childcare centres, which have been categorised based on their level of innovativeness and 
implementation? 
At two-year follow-up, is there a difference in school well-being of children from different 
childcare centres, which have been categorised based on their level of innovativeness and 
implementation? 
 
Cost-effectiveness evaluation: 
- Will HCCF be cost-effective? 
 
Comparison with original HPSF project: 
- Will the (cost-)effectiveness of HCCF be comparable with the (cost-)effectiveness of the original 
HPSF intervention? 
2. METHODS 
2.1 Study procedure/study design 
          The current study involves twelve childcare centres from the Prisma educational board, which 
are all located in Peel en Maas. The childcare centres are selected based on their expressed interest 
to participate in the project. The childcare centres are free to choose if, when and how they want 
to implement changes fitting HCCF. To study programme effectiveness, a non-randomised trial will 
be executed. Instead of true intervention and control childcare centres, after the project, the centres 
will be divided into groups based on their implementation phase. This division will be based on the 
Diffusion of Innovations Theory by Rogers (1995). According to Rogers, there are five types of 
adopters, which all have different adoption rates of a given innovation. From fast to slow adoption 
rate, these types of adopters are: innovators, early adopters, early majority, late majority and 
laggards. These adopters vary in adoption rate due to a difference in innovativeness; the degree to 
which an individual/organisation adopts a new idea (35). When looking at the Prisma childcare 
centres, it is likely that some childcare centres will adopt changes fitting HCCF earlier than others. 
Therefore, the different childcare centres can be categorised using Rogers’ categories, which will 
facilitate comparison between the different childcare centres. It is expected that the childcare 
centres can be divided in three categories: innovators/early adopters, early/late majority and 
laggards.  
The total study duration will be four years, of which roughly the first six months are preparation and 
the last year is evaluation. Therefore, data will be collected for approximately two years. Figure 1 
provides an overview of the study. 

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2.2 Recruitment and selection of participants 
Study population 
          A closed design will be used, meaning that at baseline (T0), all children in study year four to six 
of the Prisma childcare centres will be invited to participate in the study. At T1, these children will 
be students in study year five to seven, and at T2 they will be in study year six to eight. Based on the 
amount of children enrolled in school year 2019/2020, approximately 685 children are eligible to 
participate in the study. 
Screening/selection 
          Both researchers and teachers will motivate parents/caregivers and children to enrol in all 
scientific measurements. Researchers will visit every childcare centre to inform teachers and 
children about the measurements. Children from study years four to six will receive a brochure from 
researchers with information about the research that is appropriate for their parents/caregivers as 
well as for themselves. Experience from the HPSF trial showed that this personal approach of 
researchers directly motivating children and teachers facilitated recruitment of participants. Besides 
motivating children and teachers through childcare centre visits, researchers will join regular, 
already-planned information meetings for parents at the childcare centres. If needed, new 
information meetings for parents will be organised as well. In this way, parents will be informed and 
encouraged to participate in the research. 
Inclusion- and exclusion criteria  
In order to be eligible to participate in the study, a subject must meet all of the following criteria: 
- 
Student of study year four to six at one of the participating childcare centres of Prisma; 
- 
Informed consent signed by both caregivers. 
 

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No exclusion criteria are applicable as this is a real-life study and all students who meet the inclusion 
criteria will be included for participation in this study.  
 
 
Number of anticipated participants 
          Childcare centres are free to choose if, when and to what degree they implement HCCF 
changes in their childcare centre. After data collection, the twelve childcare centres will be divided 
into three categories based on the Diffusion of Innovations theory (innovators/early adopters, 
early/late majority, laggards) (35). Because this categorisation occurs after data collection, it cannot 
yet be predicted which childcare centres will fall under which category. However, based on the 
childcare centres’ intentions that have become clear during preliminary discussions about the 
project, three potential scenarios can be illustrated where childcare centres are categorised within 
the three groups. These scenarios are further illustrated in the light of three sample size calculations 
that allow for clustered sampling. For the calculations, the following website is used: 
http://www.sample-size.net/means-effect-sizeclustered/ (36). 
 
The sample size calculation was based on the primary outcome, i.e. to detect a difference in mean 
absolute BMI z-score between innovators/early adopters and laggards after two years intervention. 
The following general assumptions were used for the sample size calculation: 
- 
Independent-samples t-test on difference in absolute BMI z-scores; 
- 
Children are nested within schools; 
- 
A significance level (alpha) of 0.05; 
- 
A power of 80%; 
- 
A dropout rate of 10%, as based on dropout rates observed by Bartelink et al.(33); 
- 
An Intraclass Correlation Coefficient of 0.01, as based on Amorim et al. (37); 
- 
Unequal cluster sizes with a relative efficiency of 90% (38); 
- 
An average absolute BMI-z of 0.76 and an SD of 0.60 in the population (as no data was 
available for the population in Peel en Maas, these values were calculated over all children 
aged between 4 and 11 living in region Parkstad who visited the Youth Health Department in 
2013).  
 
Scenario 1 
- 
Innovators/early adopters: three childcare centres, number of participants (N1)=120 
- 
Laggards: four childcare centres, number of participants (N3)=220 
- 
Average size of each cluster (m): 50 
- 
With these assumptions we can demonstrate a Cohen’s d of 0.369, which means we can 
detect medium effect sizes on absolute BMI z-scores. A difference in mean absolute BMI z-
score of 0.22 between innovators/early adopters and laggards can be detected. The 
detection of this difference is feasible in this population, as in a school-based longitudinal 
study with comparable intervention components, a mean difference between intervention 
and control group of -0.26 (CI 95%: 0.32, -0.21) BMI z-score was found (39).  
 
Scenario 2 
- 
Innovators/early adopters: four childcare centres, number of participants (N1)=217 
- 
Laggards: four childcare centres, number of participants (N3)=217 
- 
Average size of each cluster (m): 55 
- 
With these assumptions we can demonstrate a Cohen’s d of 0.331, which means we can 
detect medium effect sizes on absolute BMI z-scores. A difference in mean absolute BMI z-
score of 0.20 between innovators/early adopters and laggards can be detected. The 
detection of this difference is feasible in this population, as in a school-based longitudinal 
study with comparable intervention components, a mean difference between intervention 
and control group of -0.26 (CI 95%: 0.32, -0.21) BMI z-score was found (39).  

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Scenario 3 
- 
Innovators/early adopters: four childcare centres, number of participants (N1)=217 
- 
Laggards: five childcare centres, number of participants (N3)=303 
- 
Average size of each cluster (m): 55 
- 
With these assumptions we can demonstrate a Cohen’s d of 0.314, which means we can 
detect medium effect sizes on absolute BMI z-scores. A difference in mean absolute BMI z-
score of 0.19 between innovators/early adopters and laggards can be detected. The 
detection of this difference is feasible in this population, as in a school-based longitudinal 
study with comparable intervention components, a mean difference between intervention 
and control group of -0.26 (CI 95%: 0.32, -0.21) BMI z-score was found (39).   
 
2.3 Data collection 
Methods 
          As the present study’s results will be compared with the results of the HPSF quasi-experimental 
trial (NCT02800616), the majority of the outcome measures and data collection methods used in the 
present study will be equal to the outcome measures and data collection methods used in the HPSF 
trial. The main difference with the original HPSF trial is the fact that the amount of measurements 
within this project will be smaller than in the original trial.  
 
Study Procedures 
          As shown in Table 1, outcome measurements will be gathered via various sources. Via the 
school system, data will be gathered regarding background variables and school absenteeism, which 
was also done in the HPSF trial. At Prisma, one contact person is assigned for HCCF. This person is 
also responsible for data supply for this study. With regard to the data collected from the school 
system, a data transfer agreement between educational board Prisma and Maastricht University has 
been composed and will be signed after ethical approval of the study has been obtained.   
          The majority of the additional data will be gathered during a ‘research week’ in the class. All 
measurements in children will be administered during class hours. At the beginning of this week, 
participants will receive two questionnaires that are similar to those used in the HPSF trial. The 
estimated time to complete these questionnaires is 40 minutes. The questionnaires contain 
questions regarding children’s PA and dietary behaviours and children’s well-being. Unlike in the 
HPSF trial, where the questionnaires were filled out in writing, the questionnaires will be completed 
digitally in the current study. This is done as all children have access to a tablet with a working WIFI-
connection. Filling out the questionnaires digitally will limit time and effort for both participants and 
researchers. Most children will fill out the questionnaires independently. However, the children in 
study year four will fill out the questionnaires together with a researcher in the class. Next to these 
two questionnaires, children will fill out a short questionnaire regarding their psychosocial 
determinants of fruit and vegetable intake. This questionnaire will be administered in writing during 
the first research week, three weeks after the first research week and three months after the first 
research week. Measurements of bodyweight, height and waist/hip circumference will be done 
during the research week, using the same protocol that was used in the HPSF trial and by integrating 
measurements in the school hours that are allocated to PA education. A team of researchers will 
supervise administration of all measurements. The researchers will be trained according to a strict 
protocol (equal to the HPSF protocol) to prevent interrater differences. Additionally, trained 
research assistants will observe the schoolyard during lunch breaks to investigate any differences in 
children’s free play. Parents/caregivers will also receive a digital questionnaire (similar to the 
questionnaire used in the HPSF trial) during the research week. The digital questionnaire contains 
questions regarding children’s PA and dietary behaviours and children’s health and well-being. 
Parents/caregivers are asked to complete the questionnaire within ten days. They can return the 
questionnaire online, or if preferred, by means of a letterbox in the school or regular postal mail. 

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Teachers will receive a short online questionnaire regarding their students’ behaviour in class (e.g., 
concentration during lessons, class atmosphere), their activities regarding health in class and their 
appreciation of the project. Pedagogical employees will also receive a short online questionnaire 
assessing their appreciation of the project. Lastly, childcare centre directors will receive a 
questionnaire in which they are asked to describe the childcare centre’s health-related policies. 
Data collection 
          The principal investigator, together with research assistants and students, will collect all data 
for this study. 
Standardising 
          The researchers will be trained according to a strict protocol to prevent interrater differences. 
This protocol is equal to the protocol used in the original HPSF trial and is therefore already available 
for use. 
 
2.4 Data analyses 
Data inspection 
          Extreme and missing values will be identified and handled in IBM SPSS Statistics for Windows 
(version 25, IBM Corp, Armonk, NY, USA). This will be done using the same syntaxes that were used 
in the HPSF trial. Using these syntaxes, missing values will automatically be coded, while 
differentiating between system missing values and user missing values. The cut-off scores for 
extreme values of questionnaires and anthropometric measurements used in the HPSF trial will 
again be used in the current study. Additionally, longitudinal cleaning checks will be executed. 
Normal distribution 
          Normal distribution of the data will be tested in IBM SPSS Statistics for Windows (version 25, 
IBM Corp, Armonk, NY, USA) using histograms and Q-Q plots. 
Descriptive statistics 
          Using IBM SPSS Statistics for Windows (version 25, IBM Corp, Armonk, NY, USA), descriptive 
statistics will be used to describe participants’ background characteristics. 
(Interim)analyses 
          Linear mixed model analysis techniques will be used to assess the longitudinal effect of HCCF 
on numerical outcome variables, as this technique corrects for correlation within individuals within 
groups, which occurs in repeated-measures research designs. Another advantage of this technique 
is that it naturally handles missing values, in case data are missing at random. Since measurements 
are repeated within participants, who are nested within childcare centres, we use a three-level 
model with childcare centres as third level, participants as second level and measurements as first 
level. The fixed part of the model consists of group (distribution based on Diffusion of Innovations 
Theory), time (time-points at which the measurements are taken) and the interaction term 
group*time. Baseline variables that are related to missing data and/or outcome will also be included 
to obtain unbiased results and/or to gain precision. As for the random part of the model, a random 
intercept on childcare centre level will be included next to an unstructured covariance structure for 
the repeated measurements.  
For categorical outcome variables, a logistic mixed model analysis technique will be used, where the 
model is similar as described for the numerical outcome variables. 
Coding and interpretation 
          All qualitative data will be recorded, transcribed and coded using Nvivo software. Coding will 
be performed by two independent researchers. Peer consultation between researchers will 
frequently take place. Major themes and discrepancies will be discussed with a third senior 
researcher. All researchers involved in data collection and analyses will keep a self-reflective diary 
to evaluate their own subjective views on the interpretation of the data. 
Software programme 
          Quantitative data will be analysed using IBM SPSS Statistics for Windows (version 25, IBM Corp, 
Armonk, NY, USA). Qualitative data will be analysed using Nvivo software. 

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2.5 Data management 
Location 
          To assure correct and safe data management and to ensure that the highest standards of academic 
integrity are maintained, a data management plan according to the FAIR principles (Findable, Accessible, 
Interoperable, and Reusable) will be developed for this study. This plan outlines the plans for storage, sharing 
and preservation of the data during and after the study. Additionally, it describes the security measures that 
will be taken and the restrictions that will apply given the nature of the data. 
All data will be stored according to the Maastricht University Data Management Guidelines (Table 2). 
 
Table 2: Storage Locations and Back-Up 
 
Non-digital data 
(e.g., paper) 
Digital data 
Back-up 
Non-sensitive 
data 
No restrictions 
No restrictions 
Network discs 
Sensitive, 
pseudonymised 
data 
Locked closet in 
a locked room 
Only on network discs. When the 
file size is too large to store on 
network discs, an alternative and 
safe storage location will be 
chosen after consultation of the 
principal investigator. 
Network discs 
Sensitive, 
pseudonymised 
data with ID 
Locked closet in 
a locked room 
Only on network discs. When the 
file size is too large to store on 
network discs, an alternative and 
safe storage location will be 
chosen after consultation of the 
principal investigator. 
Network discs 
Sensitive data 
with personal 
data 
Locked closet in 
a locked room 
Only on a separate network disc. 
Only the principal investigator 
and the coordinating investigator 
have access to this data.  
 
Only on a separate network 
disc. Only the principal 
investigator and the 
coordinating investigator 
have access to these back-
ups.  
Data access 
          All researchers involved in data collection procedures during the project will have access to research 
data. The principal investigator, the coordinating investigator and the research assistants will have access to 
the complete data set (i.e., sensitive data with personal data). The project leader will have access to the 
pseudonymised data set. 
Data storage 
          All data will be kept fifteen years after data-collection (GCP) and ten years after publication of the 
results in a peer-reviewed journal, unless a participant requests otherwise as stated in article 455 book 7 of 
the Civil law book (in Dutch: Burgerlijk Wetboek). No human material will be gathered during this study.  
Data protection 
          All data will be stored and transported (Table 3) according to the Maastricht University Data 
Management Guidelines. All research data will be stored separate from delicate, private information and will 
be handled confidentially according to the Dutch Personal Data Protection Act (Wet Bescherming 
Persoonsgegevens). As previously mentioned (Table 2), sensitive data will be stored in restricted, locked 
environments to keep them inaccessible for people not involved in the study.  
 
Table 3: Storage Mediums and Transport 

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Email 
Encrypted transport on 
mobile device 
Cloud and FTP 
Non-sensitive data 
No restrictions 
No restrictions 
Only in cloud and FTP services 
offered and approved by ICTS  
Sensitive 
pseudonymised data 
No restrictions 
No restrictions 
Only in cloud and FTP services 
offered and approved by ICTS 
Sensitive 
pseudonymised data 
with ID 
Permitted when 
data is 
encrypted* 
Permitted when data is 
encrypted* and only 
when strictly necessary 
Only in cloud and FTP services 
offered and approved by ICTS 
Sensitive data with 
personal data 
Not permitted 
Permitted when data is 
encrypted* and only 
when strictly necessary 
Only in cloud and FTP services 
offered and approved by ICTS, 
with encryption* 
* Encryption is done via a difficult to hack password. This contains of at least twelve characters in a non-logical order. The password 
is not used for other purposes. When a password needs to be shared with another person, this can only be done via separate 
communication channel. 
Coding 
          Before data collection at baseline, all subjects will receive an ID, which cannot be retraced to the subject 
(e.g., not based on initials and/or birth date). The principal investigator is responsible for this ID coding. In 
this way, the collected data will be pseudonymised. 
Code key 
          The keys to the subject identifier code list, the source data and passwords will be safeguarded by the 
principal investigator and coordinating investigator on their personal network discs.  
Privacy protection 
          As previously mentioned, all research data will be stored separate from delicate, private information 
and will be handled confidentially according to the Dutch Personal Data Protection Act (Wet Bescherming 
Persoonsgegevens). Sensitive data will be stored in restricted, locked environments to keep them 
inaccessible for people not involved in the study. The principal investigator will make sure that everybody 
involved in the study will sign a confidentiality agreement and will adhere to the previously developed Data 
Management Plan. She will provide the opportunity to discuss the plan and potential concerns regarding 
privacy and academic integrity in regular project meetings. If concerns or doubts arise about academic 
integrity concerning the study, researchers will contact the University Integrity Officer. 
In case of a (presumed) data breach, the principal investigator will report this as soon as possible to the 
Servicedesk ICTS of Maastricht University. Additionally, this breach will be reported to all those affected, i.e., 
the people whose data has been leaked. If there is a (presumed) data breach, Maastricht University will also 
report this to the Dutch Data Protection Authority (Autoriteit Persoonsgegevens or AP) within 72 hours. 
Data sharing 
It is not our intention to share the data of this study with other persons or organisations. 
 
 
 
 

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3. ETHICAL CONSIDERATIONS  
3.3 Burden, risk and incentives for participants 
Additional Burden for Participants 
          Participants are asked to complete a number of questionnaires and participate in 
measurements (children only). Burden of participants is minimalised by conducting measurements 
during school hours were possible (thereby minimising the extra time that needs to be invested), 
and by making measurements attractive, age-appropriate, and fun for children (e.g., by adding 
pictures to questionnaires). Additionally, burden of participants is minimalised by combining 
measurements of this study with already existing data-infrastructure, i.e., data from school systems. 
 
Risk Assessment 
          The measurements of this study are non-invasive. No risks are involved in any of the 
measurement instruments of this study. Stakeholders (e.g., childcare centre directors, teachers, 
parents/caregivers) have been involved in the selection of outcome measurements. The 
measurement protocol was designed while taking into account both a minimal burden for 
participants and relevant high-quality scientific output for stakeholders.  
 
Incentives 
          Participants will not receive a (financial) compensation for completion of the measurements.  
3.4 Participants’ consent 
Approaching 
participants 
          Parents/caregivers will be informed about the study by two 
information brochures (i.e., a brochure for parents/caregivers and an age-
specific brochure for children). These brochures will be distributed to all 
children of study years four to six. Researchers will distribute these 
brochures while providing additional information about the research and 
giving potential participants the opportunity to ask questions. 
          Besides informing children and teachers through childcare centre 
visits, researchers will join regular, already-planned information meetings 
for parents at the childcare centres. If needed, new information meetings 
for parents will be organised as well. In this way, parents will be informed 
and encouraged to participate in the research. 
Informing 
participants 
          Parents/caregivers will be informed about the study both personally 
(by researchers attending regular, already-planned information meetings 
for parents at the childcare centres and if needed via new information 
meetings) and by two information brochures (i.e., a brochure for 
parents/caregivers and an age-specific brochure for children) which 
children receive from researchers visiting the childcare centres and/or from 
their teachers. Informed consents (IC) will only be send out once the 
representative advisory boards of the school has given their approval of 
HCCF. Parents/caregivers are asked for consent by sending an IC to the 
researchers.  
          Children will be informed about the study by researchers, their 
parents/caregivers and their teachers. During the entire study, the principal 
investigator is the contact point regarding study-related questions. 
Consideration time 
          Participants will be given a period of ten days to consider their 
decision. If no IC has been returned to the principal investigator after ten 
days, parents/caregivers will receive a reminder. 
Signing informed 
consent 
          ICs will be signed in duplicate by the principal investigator and both 
parents before baseline measurements. One copy of this signed IC will be 
stored by the principal investigator, while the second copy is for the 
participant. 

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4. VALORISATION AND PUBLICATION 
Valorisation 
          This unique topic is of great societal and scientific importance. It may affect cultural aspects of 
our society i.e., norms and values about education and parenting. In this way, it may alter the 
traditional Dutch educational system by enabling the implementation of structured health-
promoting activities in the school environment. By developing guidelines for implementing HCCF 
changes in various school-contexts, the study’s results can be beneficial for schools all throughout 
the Netherlands, thereby increasing the study’s potential impact. If HCCF is effective at improving 
the child-related outcome measures monitored in this study, widespread implementation of HCCF 
might improve children’s overall health. Considering that lifestyle habits formed during childhood 
often track into adulthood, HCCF might result in a healthier adult population in the long run, thereby 
reducing health care costs and costs associated with sick leave (WHO, 2006, 2017, 2018). 
Publication 
          It is intended to report the study’s results at conferences such as the Nederlands Congres 
Volksgezondheid (NCVGZ) and the International Society of Behavioural Nutrition and Physical 
Activity (ISBNPA) conference. Additionally, it is intended to publish articles regarding the study’s 
results in journals such as BMC Public Health, International Journal of Behavioural Nutrition and 
Physical Activity (IJBNPA) and/or PLOS Medicine/PLOS One. 
 
 

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Appendix I. Table Data Collection 
 
 
Table 1. Data Collection Methods 
 
School 
Additional 
Time point 
Parents 
Children 
Teachers/childcare 
centre staff 
Background variables 
Birth date 
X 
 
 
 
T0, T1, T2 
School class 
X 
 
 
 
T0, T1, T2 
Sex 
X 
 
 
 
T0, T1, T2 
Ethnicity 
 
X 
 
 
T0, T1, T2 
Family composition 
 
X 
 
 
T0, T1, T2 
Postal code home 
X 
 
 
 
T0, T1, T2 
Socio-economic status (parental education level) 
 
X 
 
 
T0, T1, T2 
Childcare use outside school hours 
 
 
X 
 
T0, T1, T2 
Sleep 
 
X 
 
 
T0, T1, T2 
School absenteeism 
X 
 
 
 
T0, T1, T2 
General health 
Weight  
 
 
X 
 
T0, T1, T2 
Length  
 
 
X 
 
T0, T1, T2 
Waist/hip circumference  
 
 
X 
 
T0, T1, T2 
Visits to GP, disease status 
 
X 
 
 
T0, T1, T2 
Quality of life (parental PedsQL) 
 
X 
 
 
T0, T1, T2 
Behavioural problems (parental SDQ) 
 
X 
 
 
T0, T1, T2 
Physical activity 
PA level (PAQ-C + additional questions) 
 
 
X 
 
T0, T1, T2 
PA behaviour  
 
X 
 
 
T0, T1, T2 
Free play during lunch time (structured observations) 
 
 
X 
 
T0, T2 
Dietary Behaviour 
Food + water consumption, habits and preferences 
 
 
X 
 
T0, T1, T2 
Lunch intake 
 
 
X 
 
T0, T1, T2 
APPENDICES 

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Food + drinking behaviour 
 
X 
 
 
T0, T1, T2 
Psychosocial determinants of fruit and vegetable intake 
 
 
X 
 
-T0 
-Three weeks after T0  
-Three months after T0 
School well-being 
Class atmosphere and students’ behaviour (My Class Inventory-Short Form for 
Teachers, adapted version + self-constructed questions) 
 
 
 
X 
T0, T1, T2 
Satisfaction, concentration, bullying behaviour (Multidimensional Students’ Life 
Satisfaction Scale: School Satisfaction Subscale + self-constructed questions) 
 
 
X 
 
T0, T1, T2 
Process evaluation 
Health-related rules, regulations and practices at childcare centre 
 
 
 
X 
T0, T1, T2 
Teachers’/Pedagogical employees’ health-related practices at childcare centre, 
process parameters and satisfaction 
 
 
 
X 
T0, T1, T2 
Interviews and observations to evaluate satisfaction and process parameters 
 
 
 
X 
Between T1 and T2