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Daily physical activity is vital for the health and development of children. However, many children are inactive. Previous attempts to achieve sustained increases in daily physical activity in children have been ineffective. Join Us: Move Play (JU:MP) is a whole-system, complex, community-based intervention aiming to increase the physical activity levels of children aged 7 to 11 years who live in areas of Bradford, England, which are multicultural and have high levels of deprivation.
The purpose of this quasiexperimental controlled trial is to assess whether the JU:MP program increases primary school children’s physical activity.
The study has a 2-arm, quasiexperimental, nonblinded, nonequivalent group design and will be conducted with primary school children aged 5 to 11 years at 3 timepoints, including baseline (before intervention), 24 months (during intervention), and 36 months (after intervention). Children attending primary schools within the intervention area will be invited to participate. Children attending similar schools within similar neighborhoods based on school and community census demographics (deprivation, free school meals, and ethnicity) outside of the JU:MP geographical area will be invited to participate in the control condition. At each timepoint, consenting participants will wear an accelerometer for 7 consecutive days (24 hours a day) to measure the primary outcome (average daily moderate-to-vigorous physical activity). Multivariable mixed effects linear regression will be applied to estimate differences in the primary outcome between the 2 arms at 24 months and 36 months on an intention-to-treat basis. The secondary outcome analysis will explore changes in socioemotional well-being (teacher reported), quality of life (parental/carer reported), and other contextual factors (parents/carer reported), as well as segments of the day activity, sleep, sedentary screen time, frequency of places to be active, parent practices (nondirective support and autonomy support), social cohesion, and neighborhood walking/exercise environment.
Recruitment occurred from July 2021 to March 2022, and baseline data were collected from September 2021 to March 2022. As of March 2022 (end of baseline data collection), a total of 1454 children from 37 schools (17 intervention schools and 20 control schools) have been recruited. The first follow-up data collection will occur from September 2023 to March 2024, and the second and final follow-up data collection will occur from September 2024 to March 2025. Data analysis has not begun, and the final results will be published in December 2025.
This article describes the protocol for a quasiexperimental controlled trial examining a novel whole-system intervention.
ISRCTN ISRCTN14332797; https://www.isrctn.com/ISRCTN14332797
DERR1-10.2196/43619
Daily physical activity, particularly of moderate-to-vigorous intensity, is very beneficial for the physical, emotional, and social development of young people [
Worryingly, levels of inactivity are high across the globe [
In response to the growing realization of a need for whole-system approaches to physical activity, Sport England (a nondepartmental public body, which is the largest funder of physical activity and sport programs in England) funded 12 local delivery pilots over a 5-year period (2019-2024), to design and implement a whole-system place-based approach to reduce physical inactivity and health inequalities. All of the selected pilot areas are characterized by high levels of deprivation, but target different populations (eg, older people and whole communities), with the Join Us: Move Play (JU:MP) program being delivered in Northern areas of the City of Bradford, targeting children and young people aged 5 to 14 years. Bradford is the 7th largest metropolitan district in England and is home to more than half a million people. A quarter of Bradford’s population is under the age of 16 years, making Bradford the “youngest” city in the United Kingdom [
The aim of this quasiexperimental trial is to explore whether JU:MP is effective at increasing physical activity among children aged 5 to 11 years. The specific research objectives are as follows:
Determine the effectiveness of JU:MP to increase device-measured (accelerometry) mean average daily moderate-to-vigorous physical activity among children aged 5 to 11 years 24 months and 36 months after the implementation of a whole-system community intervention.
Determine the effectiveness of JU:MP to improve secondary outcomes among children aged 5 to 11 years 24 months and 36 months after the implementation of a whole-system community intervention. The secondary outcomes are as follows: (1) mean average daily, weekday, and weekend day sedentary time (device measured [accelerometry]); (2) mean average daily, weekday, and weekend day light physical activity (device measured [accelerometry]); (3) weight status and body fat level (waist circumference and BMI); (4) socioemotional well-being, including prosocial behavior, emotional problems, behavioral problems, peer problems, and hyperactivity/inattention (teacher reported); and (5) children’s quality of life (parental reported).
Undertake exploratory subgroup analysis (ie, neighborhood level and school level) investigating the change in the primary and secondary outcomes.
Investigate the potential meditating effects of changes in contextual factors (JU:MP is seeking to change; parental reported): (1) home physical activity, (2) school time physical activity, (3) children’s sedentary screen time behaviors, (4) active travel and street physical activity, (5) parent practices (nondirective support and autonomy support), (6) neighborhood social cohesion, (7) neighborhood walking/exercise environment, (8) religious setting physical activity, (9) physical activity during sports and recreation, and (10) park/green space physical activity.
A more comprehensive description of the JU:MP program can be found in the report by Hall et al [
The JU:MP program (
SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) diagram illustrating the design and timescales of the JU:MP controlled trial. JU:MP: Join Us: Move Play.
Join Us: Move Play (JU:MP) program model. CEM: community engagement manager; PA: physical activity.
The study has a 2-arm (intervention [JU:MP] and control), quasiexperimental, nonblinded, nonequivalent group design with 3 waves of data collection (baseline [before intervention], 24 months [during intervention], and 36 months [after intervention]).
Join Us: Move Play (JU:MP) program neighborhood, quasiexperimental, nonequivalent group trial. EQ-5D-Y: EuroQol 5-dimension youth version; PedsQL: Pediatric Quality of Life Inventory.
The research will be situated within primary schools located across the Northern English County of West Yorkshire. Recruitment and data collection are taking place through primary schools as they are located within JU:MP neighborhoods, and children tend to live in close proximity to the school they attend. Primary schools allow access to a large number of children as potential participants, and previous research has shown that it is feasible and acceptable to conduct physical activity trials through primary schools [
The JU:MP program is operating in 8 distinct neighborhoods. The 3 neighborhoods eligible for participation in this effectiveness trial are the 3 direct-delivery neighborhoods of JU:MP. Control neighborhoods will be based on local authority wards (local areas with elected officials representing the local area) and be in the county of West Yorkshire in order to ensure that neighborhoods would be politically and geographically similar to the JU:MP neighborhoods. Other neighborhoods/wards in Bradford have been excluded due to potential intervention contamination. Control neighborhoods must ideally have similar characteristics to the JU:MP neighborhoods to maximize internal validity. The process of identifying control neighborhoods will include pooling state-funded primary school census data [
Once the neighborhoods are selected, government-funded primary schools located in the JU:MP and control neighborhoods will be invited to participate in the research. The number of control schools recruited will be dependent on the recruitment of intervention schools in the neighborhoods to the study. Private and designated special schools have been excluded from this study. Identified schools will be contacted via standardized emails and follow-up phone calls (48 hours later) to request and arrange an in-person/virtual meeting to discuss the study and school-level consent. The primary schools in the JU:MP neighborhoods will be part of the JU:MP program and will receive whatever benefits may be derived from participating in the program. The primary schools within the control areas will not be offered access to the JU:MP program and must agree in principle not to commit to any whole-system school physical activity research in the next 3 years. To incentivize such a commitment, each of the primary schools in the control areas will be offered a total of £600 (US $727), with the caveat that this should not be spent on physical activity provision (physical education, active travel, after school clubs, etc) for the duration of the 3-year study. The £600 (US $727) payment will be split into 3 instalments of £200 (US $242) to be paid after the competition of each of the 3 study data collections (baseline, 24-month follow-up, and 36-month follow-up). If the school agrees to participate in the study, arrangements will be made to begin recruiting children.
All children in years 1, 2, and 3 (ages 5-8 years) at recruited schools will be invited to participate. Members of the research team will agree with school leadership on how best to speak and discuss about the study with all children in the school, but this will likely involve a researcher speaking to each class individually or the year groups collectively during a school assembly. Children will be provided with printed study information sheets and consent forms to take home for their parents/carers. The research team will ensure all forms are distributed to each class teacher and forms are sent home with children in book bags or school planners/diaries so that parents/carers can make an informed decision about whether their children can participate in the study. To ensure parents/carers have an opportunity to discuss the study with the research team, a time and day when they can attend a presentation and a question-and-answer session (within the school or virtually) will be arranged within a week of the information sheets and consent forms being issued. The research team will also seek to agree on times and days when researchers can be present in the school playground before and after school (pick up and drop off time). Short videos will also be produced, which will explain the study, and schools will be asked to distribute links of the videos (ie, YouTube) to parents. For children to participate, their parents/carers must provide informed consent. On the day of data collection, 2 members of the research team will discuss the study with each child and obtain verbal assent. For children with special educational needs/disabilities and those who do not have the capacity to provide assent, the research team will instead seek assent from a school staff member familiar to the child, with the child present. All children participating will receive a gift “goodie bag” worth an estimated £2 (US $2.42), which will include nonphysical activity–related items such as a book, stickers, and other similar items. The goodie bag will be given to each child at each data collection timepoint (baseline, 24 months, and 36 months).
The primary outcome assessment of this study will involve waist-worn accelerometry. At each timepoint, researchers will support children to fit an accelerometer (ActiGraph) worn on a belt around the child’s waist, just above the right hip. Children will receive a demonstration by a member of the research team, showing them how to fit the accelerometer. Children will be asked to wear the accelerometer for 7 consecutive days (24 hours a day; only to be removed for showering, bathing, and swimming). Children will be told that if it is uncomfortable to sleep in, they can remove it for sleep and wear it when they wake-up. ActiGraph data will be analyzed using ActiLife v6 (ActiGraph) and downloaded in 60-second epoch files. Sleep will be removed using validated sleep period–detection algorithms [
After the receipt of parental/carer consent, researchers will request school-stored demographic data, such as date of birth, unique pupil number (linked to health records), biological sex, ethnicity, home postcode (for IMD calculation), child’s disability or special educational needs, and receipt of government-funded free school meals, from participating schools. The immediate request is to ensure the research team can plan provisions for any children with any additional needs during testing. On the first day of data collection, the research team will ask schools to provide the most recent attendance records and educational attainment data, and a copy of the class timetable for 2 weeks starting from the date of data collection (for accelerometry data collection). Anthropometric measurements will include weight, height, BMI, and waist circumference; all will be measured by trained researchers within the school setting. Weight will be assessed barefoot and in light clothing using a digital scale (eg, Tanita body composition analyzer SC-240MA III). Height will be measured unshod, with the head placed in the correct position, on a Seca 213 stadiometer (graduation=1 mm). BMI will be calculated and converted to a BMI percentile and z-score based on UK reference data [
In order to measure children’s socioemotional well-being, class teachers of the recruited children will be asked to complete an assessment of the child’s behavior and socioemotional development using the strengths and difficulties questionnaire (SDQ) [
On the day of data collection, children will be given a questionnaire to give to their parents/carers, which takes an estimated 20 minutes to complete. Parents/carers will complete this questionnaire at all 3 timepoints. Parents/carers will be asked to complete the questionnaire about their children’s life, rather than asking the children themselves, due to the young age of the children at baseline (5-8 years), which limits questionnaire comprehension and increases the risk of social desirability bias. The purpose of collecting such questionnaire data is to attempt to understand potential mediating factors of children’s accelerometer-measured physical activity. The content aligns with key components of JU:MP. This questionnaire has been piloted with groups of parents/carers living in West Yorkshire and has been deemed acceptable. The questionnaire comprises 6 sections. The first section relates to personal information of the children, including their name, school class, teacher’s name, age, and relationship with the person completing the questionnaire. The second section is the youth activity profile (YAP) [
A sample size calculation was performed using Stata V.16 (StataCorp), with the function “power two means cluster,” factored in 6 clusters (3 intervention neighborhoods and 3 control neighborhoods), and a 5% 2-sided alpha, as well as an assumed control average daily value of moderate-to-vigorous physical activity of 53.7 minutes, a SD of 19.7, and an intracluster correlation (ICC) value of 0.007, which was conservatively rounded up to 0.01. As the JU:MP project is a neighborhood/community-level intervention and no previous studies using accelerometry as an outcome assessment among children or young people could be identified, the values of average daily moderate-to-vigorous physical activity, SD, and ICC were derived from an unpublished pilot study (sample size n=564; 3 neighborhoods; 12 primary schools). The missingness of data was conservatively factored into the sample size calculation by assuming 30% accelerometer noncompliance at baseline, followed by further 50% loss of data (30% accelerometer noncompliance and 20% attrition) at both the 24-month and 36-month follow-ups. The parameters outlined led to a minimum recommended sample of 1200 children (600 per condition, 200 per neighborhood, and 32 per school) for adequate power (80%) to detect a change of at least 10 minutes in the primary outcome of average daily minutes of moderate-to-vigorous physical activity at both the 24-month and 36-month follow-ups.
Data will be entered electronically with a double data entry protocol using REDCAP software. Data will be kept on a secure file storage system, which will also be password protected. Data will be anonymized by the assignment of a unique identification number (study ID) to each participant. The primary comparative analysis (objective 1) will be performed on an intention-to-treat basis, including all participants recruited and without imputation for missing data. Multivariable mixed effects linear regression will be used to estimate differences in the primary outcome (accelerometer-assessed mean daily minutes of moderate-to-vigorous physical activity) between the intervention and control groups. Demographic variables of gender and ethnicity will be treated as random effect variables, and baseline moderate-to-vigorous physical activity, age, accelerometer wear time, BMI z-score, school, neighborhood, and condition will be treated as fixed effect variables. Similar analyses will be repeated for secondary outcomes (objective 2). A sensitivity analysis, using a suitable imputation method, will be conducted to assess the effect of missing data.
This study and all processes were given ethical approval by the University of Bradford Research Ethics Committee (Humanities, Social, and Health Sciences Research Ethics Panel; reference: E891). Informed consent will be sought from schools and parents. Children (participants) will also be asked to provide assent at every data collection timepoint. Schools in the control condition will be paid £600 (US $727) overall (£200 [US $242] for every data collection [baseline, 24-month follow-up, and 36-month follow-up]), and children will be given a “goodie bag” (includes books, stationery, and stickers) worth £2 (US $2.42) as a thank you each time they complete data collection. All data collected will be deidentified and anonymized by using ID numbers and storing all data on secure National Health Service servers, and only the principal investigator and senior researcher will have access to confidential information. All questionnaire data will be double data entered into secure databases created within RedCap.
This study has been registered at ISRCTN (ISRCTN14332797). Recruitment occurred from July 2021 to March 2022, and baseline data collection occurred from September 2021 to March 2022. As of March 2022 (end of baseline data collection), a total of 1454 children from 37 schools (17 intervention schools and 20 control schools) have been recruited. The first follow-up data collection will occur from September 2023 to March 2024, and the second and final follow-up data collection will occur from September 2024 to March 2025. Data analysis has not begun, and the final results will be published in December 2025.
This paper describes the protocol for a quasiexperimental, nonblinded, nonequivalent group design trial of the JU:MP program, a complex, community, whole-system children’s physical activity intervention. The research outlined in this protocol seeks to explore whether the JU:MP program is effective at increasing the physical activity levels of children aged 5 to 11 years. The recruitment of this trial and baseline data collection have been completed, with 1454 children from 37 schools (17 intervention schools and 20 control schools) being recruited. This number indicates overrecruitment according to the power-calculated target of 600 children per condition (N=1200) and puts the future of this trial in good stead for follow-ups at 24 and 36 months.
Many children and young people do not engage in enough physical activity, with those from ethnic minority backgrounds and economically deprived backgrounds being at greater risk for inactivity and related ill-health. Previous attempts to change children’s physical activity have largely been unsuccessful [
As with all research, there are limitations with the proposed work detailed in this protocol. Namely, the quasiexperimental design of the work naturally has an increased risk of bias when compared with a randomized controlled trial, which is the gold standard way to detect the effects of programs and interventions [
Many attempts have been made by researchers, practitioners, and policy makers to address children’s physical inactivity. However, previous attempts have been unsuccessful in both intervention design and the application of complex evaluations. Lack of success leads to children’s physical activity levels stagnating or worsening, increasing the risk of ill-health and negatively impacting the growth and development of young people. Sport England, the largest funder of sports and physical activity in England, has invested significant funds in 12 geographical areas in England to increase physical activity through a place-based whole-system approach. Methodologically rigorous and high-quality research is required to examine what works, why, for whom, and in what context, in order to understand the potential of whole-system approaches for increasing children’s physical activity, and whether and how they can be replicated [
Join Us: Move Play (JU:MP) neighborhood map. A geographical map of the JU:MP neighborhood boundaries within the local delivery pilot area. The depicted map is adapted from the QGIS Geographic Information System (2021) and Open Source Geospatial Foundation Project.
Directed acyclic graph showing the potential casual pathways between mediators and the outcome. JU:MP: Join Us: Move Play; MVPA: moderate-to-vigorous physical activity; PA: physical activity.
Directed acyclic graph showing the potential casual pathways between mediators and the outcome, with interconnections between mediators. JU:MP: Join Us: Move Play; MVPA: moderate-to-vigorous physical activity; PA: physical activity.
Directed acyclic graph showing the potential casual pathways between mediators and the outcome, with possible casual pathways between confounders. JU:MP: Join Us: Move Play; MVPA: moderate-to-vigorous physical activity; PA: physical activity; SES: socioeconomic status.
intracluster correlation
index of multiple deprivation
Join Us: Move Play
strengths and difficulties questionnaire
youth activity profile
We are grateful for the funding provided by Sport England to implement and evaluate the program. The authors wish to thank the JU:MP team and wider stakeholders, including colleagues within Born in Bradford and ActEarly, including Dr Brian Kelly, for their inputs in developing the trial design. This work was also supported by the UK Prevention Research Partnership (MR/S037527/1), which is funded by the British Heart Foundation, Cancer Research UK, Chief Scientist Office of the Scottish Government Health and Social Care Directorates, Engineering and Physical Sciences Research Council, Economic and Social Research Council, Health and Social Care Research and Development Division (Welsh Government), Medical Research Council, National Institute for Health Research, Natural Environment Research Council, Public Health Agency (Northern Ireland), The Health Foundation, and Wellcome.
This is not applicable at present as this is a protocol article. However, future and final data sets will be available from the corresponding author and a Born in Bradford (BiB) executive on reasonable request. Scientists are encouraged and able to use BiB data, which are available through a system of managed open access. The steps below describe how to apply for access to BiB data.
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None declared.