Early-stage studies to larger-scale trials: investigators’ perspectives on scaling-up childhood obesity interventions

Background

Pilot/feasibility studies play an important role in the development and refinement of behavioral interventions by providing information about feasibility, acceptability, and potential efficacy. Despite their importance and wide-spread use, the approaches taken by behavioral scientists to scale-up early-stage studies to larger-scale trials has received little attention. The aim of our study was to understand the role that pilot studies play in the development and execution of larger-scale trials.

Methods

We conducted interviews with childhood obesity researchers who had published pilot behavioral interventions and larger-scale trials of the same or similar interventions. Questions were asked about the role of pilot studies in developing larger-scale trials and the challenges encountered when scaling-up an intervention based upon pilot findings. Data were coded and analyzed using an inductive analytic approach to identify themes.

Results

Twenty-four interventionists (54% women, 37–70 years old, mean 20 years since terminal degree) completed a total of 148 pilot studies across their careers (mean 6.4, range 1–20), of which 59% were scaled-up. Scaling was described as resource intensive and pilot work was considered essential to successfully competing for funding by 63% of the sample (n = 15). When asked to define a high-quality pilot study, interventionists described studies that allowed them to evaluate two independent factors: components of their intervention (e.g., acceptability, feasibility) and study parameters (e.g., sample size, measures). Interventionists expressed that more process implementation measures, different study designs, and additional iterations could improve decisions to scale-up. Most agreed that pilot studies were likely to produce inflated estimates of potential efficacy though only nine interventionists provided potential solutions for decreasing inflated measures of efficacy. Suggested major causes of inflated effects included high levels of oversight in pilot studies (e.g., researcher support), reliance on subjective measures, and utilizing convenience or highly motivated samples. Potential solutions included designing pilots for real-world implementation, only conducting randomized controlled pilot studies, and pre-registering pilot studies.

Conclusions

Pilot studies purposes are multifaceted and deemed essential to obtaining funding for larger-scale trials. Clarifying the form and function of preliminary, early-stage research may enhance the productive utilization of early-stage studies and reduced drops in efficacy when transitioning to larger scale studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-022-00991-8.

24 hour movement behaviours and the health and development of pre-school children from Zimbabwean settings: the SUNRISE pilot study

Background

In 2019, the World Health Organization (WHO) released global guidelines for physical activity, sedentary behaviour and sleep for the early years. The International Study of Movement Behaviours in the Early Years, SUNRISE, aimed to assess the extent to which children aged three and four years meet the WHO global guidelines and its association with health and development.

Objectives

To assess movement behaviours in pre-school children from low-income settings in Zimbabwe and to establish associations between these movement behaviours and adiposity, motor skills and executive function.

Methods

Pre-school children/caregivers were recruited from two urban and two rural public schools respectively in Zimbabwe. The caregivers answered questions on the children's physical activity, screen time, sedentary behaviour and sleep patterns. Children's movement behaviours were objectively measured using accelerometers. Gross and fine motor skills and executive function were assessed using the Ages and Stages Questionnaire-3 and Early Years Toolbox, respectively. Focus group discussions were carried out with caregivers and teachers on the acceptability and feasibility of the study.

Results

Eighty-one children participated in the study. The proportions of children meeting the guidelines were physical activity 92%, sedentary behaviour 70%, and sleep 86%, and all guidelines combined 24%. Boys and girls were similar (p>0.05 for all variables) for all executive function variables, but rural children had significantly lower inhibition scores (p=0.026) than urban children.

Conclusion

The study adds to the growing literature on movement behaviours and associated risk factors in low-resourced settings. Further investigations of movement behaviours in this age group in Zimbabwe are recommended.

Understanding the influence of 24-hour movement behaviours on the health and development of preschool children from low-income South African settings: the SUNRISE pilot study

Background

The International Study of Movement Behaviours in the Early Years, SUNRISE, was initiated to assess the extent to which young children meet movement behaviour guidelines (physical activity, sedentary behaviour, screen time, sleep).

Objective

The South African SUNRISE pilot study assessed movement behaviours in preschool children from two low-income settings, and associations between these movement behaviours, adiposity, motor skills and executive function (EF).

Methods

Preschool child/parent pairs (n = 89) were recruited from preschools in urban Soweto and rural Sweetwaters. Height and weight were measured to assess adiposity. Physical activity was assessed using accelerometers while sedentary behaviour, screen time and sleep were assessed via parent report. Fine and gross motor development were measured using the Ages and Stages Questionnaire-3, and EF was assessed using the Early Years Toolbox.

Results

The proportion of children meeting the physical activity guideline was 84%, 66% met the sleep guideline, 48% met the screen time guideline, and 26% met all three guidelines. Rural children were more active, but spent more time on screens compared to urban children. Most children were on track for gross (96%) and fine motor (73%) development, and mean EF scores were in the expected range for all EF measures. EF was negatively associated with screen time, and gross motor skills were positively associated with physical activity.

Conclusion

The South African SUNRISE study contributes to the growing literature on 24-hour movement behaviours in SA preschool children, and highlights that these behaviours require attention in this age group.

What is the impact of professional learning on physical activity interventions among preschool children? A systematic review

The purpose of this systematic review was to investigate professional learning models (length, mode, content) offered as part of objectively measured physical childcare-based interventions. A systematic review of eight electronic databases was conducted to June 2017. Only English, peer-reviewed studies that evaluated childcare-based physical activity interventions, incorporated professional learning and reported objectively measured physical activity were included. Study designs included randomized controlled trails, cluster randomized trials, experimental or pilot studies. The search identified 11 studies. Ten studies objectively measured physical activity using accelerometers; five studies used both accelerometer and direct observation tools and one study measured physical activity using direct observation only. Seven of these studies reported statistically significant intervention effects. Only six studies described all components of professional learning, but only two studies reported specific professional learning outcomes and physical activity outcomes. No patterns were identified between the length, mode and content of professional learning and children's physical activity outcomes in childcare settings. Educators play a critical role in modifying children's levels of physical activity in childcare settings. The findings of this review suggest that professional learning offered as part of a physical activity intervention that potentially impacts on children's physical activity outcomes remains under-reported.

Flexibility is associated with motor competence in schoolchildren

Available data on the associations between motor competence (MC) and flexibility are limited and result inconclusive. This study aims to examine the relationship between flexibility and MC in children. The sample comprised 596 Portuguese children (47.1% girls) aged 9.7 ± 0.6 years. Motor competence was evaluated with the body coordination test, Körperkoordination Test für Kinder. Cardiorespiratory fitness (20-m shuttle run), muscular strength (curl-up and push-up tests), and flexibility (back-saver sit and reach and trunk-lift tests) were evaluated using the Fitnessgram Test Battery. Z-scores by age and gender for the physical fitness tests were constructed. Analysis of variance and regression analysis were performed. Participants in the healthy zone groups of both flexibility tests exhibited significantly better scores of MC than the participants under the healthy zone (P < 0.001). Back-saver sit and reach and trunk-lift Z-scores, either individually or as a sum, were significant predictors of MC (P < 0.05 for all) after adjustments for the other physical fitness components, age, body mass index, and socioeconomic status, in both genders. Our findings highlight the importance of promoting and developing flexibility, as well as the other health-related physical fitness components in schoolchildren to reach adequate levels of MC.

Effects of a 'school-based' physical activity intervention on adiposity in adolescents from economically disadvantaged communities: secondary outcomes of the 'Physical Activity 4 Everyone' RCT

BACKGROUND/OBJECTIVES:

Obesity prevention during adolescence is a health priority. The ‘Physical Activity 4 Everyone' (PA4E1) study tested a multi-component physical activity intervention in 10 secondary schools from socio-economically disadvantaged communities. This paper aimed to report the secondary outcomes of the study; to determine whether the intervention impacted on adiposity outcomes (weight, body mass index (BMI), BMI z-score), and whether any effect was moderated by sex, baseline BMI and baseline physical activity level, at 12 and 24 months.

SUBJECTS/METHODS:

A cluster randomised controlled trial was conducted in New South Wales, Australia. The school-based intervention included seven physical activity strategies targeting the following: curriculum (strategies to maximise physical activity in physical education, student physical activity plans, an enhanced school sport programme); school environment (physical activity during school breaks, modification of school policy); and parents and the community (parent engagement, links with community physical activity providers). Students' weight (kg), BMI and BMI z-score, were collected at baseline (Grade 7), 12 and 24 months. Linear Mixed Models were used to assess between-group mean difference from baseline to 12 and 24 months. Exploratory sub-analyses were undertaken according to three moderators of energy balance.

RESULTS:

A total of 1150 students (mean age=12 years) provided outcome data at baseline, 1051 (91%) at 12 months and 985 (86%) at 24 months. At 12 months, there were group-by-time effects for weight (mean difference=–0.90 kg (95% confidence interval (CI)=–1.50, −0.30), P<0.01) and BMI (−0.28 kg m⁻² (−0.50, −0.06), P=0.01) in favour of the intervention group, but not for BMI z-score (−0.05 (−0.11; 0.01), P=0.13). These findings were consistent for weight (−0.62 kg (−1.21, 0.03), P=0.01) and BMI (−0.28 kg m⁻² (−0.49, −0.06), P=0.01) at 24 months, with group-by-time effects also found for BMI z-score (−0.08 (−0.14; −0.02), P=0.02) favouring the intervention group.

CONCLUSION:

The PA4E1 school-based intervention achieved moderate reductions in adiposity among adolescents from socio-economically disadvantaged communities. Multi-component interventions that increase adolescents' engagement in moderate-to-vigorous physical activity (MVPA) may assist in preventing unhealthy weight gain.

Objectively measured sedentary behaviour and health and development in children and adolescents: systematic review and meta-analysis

Sedentary behaviour has emerged as a unique determinant of health in adults. Studies in children and adolescents have been less consistent. We reviewed the evidence to determine if the total volume and patterns (i.e. breaks and bouts) of objectively measured sedentary behaviour were associated with adverse health outcomes in young people, independent of moderate-intensity to vigorous-intensity physical activity. Four electronic databases (EMBASE MEDLINE, Ovid EMBASE, PubMed and Scopus) were searched (up to 12 November 2015) to retrieve studies among 2- to 18-year-olds, which used cross-sectional, longitudinal or experimental designs, and examined associations with health outcomes (adiposity, cardio-metabolic, fitness, respiratory, bone/musculoskeletal, psychosocial, cognition/academic achievement, gross motor development and other outcomes). Based on 88 eligible observational studies, level of evidence grading and quantitative meta-analyses indicated that there is limited available evidence that the total volume or patterns of sedentary behaviour are associated with health in children and adolescents when accounting for moderate-intensity to vigorous-intensity physical activity or focusing on studies with low risk of bias. Quality evidence from studies with robust designs and methods, objective measures of sitting, examining associations for various health outcomes, is needed to better understand if the overall volume or patterns of sedentary behaviour are independent determinants of health in children and adolescents.

Description and evaluation of a social cognitive model of physical activity behaviour tailored for adolescent girls

The aim of this paper was to describe and test a social cognitive model of physical activity tailored for adolescent girls. Participants were 1518 girls (aged 13.6 ± 0.02 years) from 24 secondary schools in New South Wales, Australia. Useable accelerometer (≥10 hours day(-1) on at least 3 days) and questionnaire data were obtained from 68% of this sample (N = 1035). Participants completed questionnaires assessing psychological, behavioural, social and environmental correlates of activity. The theoretical model was tested using structural equation modelling in AMOS. The model explaining accelerometer counts per minute was an adequate-to-good fit to the data (Tucker-Lewis Index = 0.89, the comparative fit index = 0.97 and the root mean square of approximation = 0.098; 90% confidence interval = 0.075-0.122) but explained only 5% of the variance in activity. There were significant model pathways from self-efficacy (r = 0.11, P = 0.01), school environment (r = 0.07, P = 0.02) and physical self-worth (r = 0.07, P = 0.04) to accelerometer counts. Although the proposed model provided an adequate-to-good fit to the data, it explained a small portion of the variance. Shared method variance may explain the larger portions of variance explained in previous studies. Future studies are encouraged to evaluate theories of physical activity behaviour change using objective measures of physical activity.

The impact of child and adolescent obesity treatment interventions on physical activity: a systematic review

Efforts to treat obesity in childhood and adolescence would benefit from a greater understanding of evidence-based strategies to modify physical activity behaviour. A systematic review was conducted to examine the impact of child and adolescent obesity treatment interventions on physical activity. Studies included were randomized controlled trials or controlled trials, with overweight and obese youth (aged < 18 years), which reported statistical analysis of free-living physical activity at pretreatment and post-treatment. Two independent reviewers assessed each study for methodological quality. Seventeen child and three adolescent studies were retrieved, half of which were conducted in the USA. Studies were characterized by small samples of limited cultural and economic diversity. Fifteen studies reported an increase in at least one physical activity outcome at post-test or follow-up. Overall, study quality was rated as low (child median score = 3/10, range = 0-9; adolescent median score = 3/10, range = 2-5) with three child studies classified as high quality (>or=6/10). Research evaluating the effect of child and adolescent obesity treatment trials on physical activity is limited in both quantity and quality. Studies testing innovative, theoretically driven treatment approaches that use robust methodologies are required to better understand generalizable approaches for promoting physical activity participation among obese youth.

Methods of the NSW Schools Physical Activity and Nutrition Survey (SPANS)

The NSW Schools Physical Activity and Nutrition Survey (SPANS 2004) (N = 5407) was a representative population survey, conducted February-May 2004, among New South Wales (Australia) school students aged 4 y-16 y. Physical activity, fitness, fundamental movement skill proficiency and food habits are all related to overweight and obesity and were a focus of this study. The last population-based survey in NSW was conducted in 1997 and use of the same measurement instruments (with the exception of food habits) allowed examination of secular trends. Overweight and obese children are at risk for a number of serious, long-term health problems, and a sub-sample (n = 500) of urban dwelling Year 10 students (mean age 15.4 years) gave a fasting blood sample which was analysed for the presence of risk factors for the metabolic syndrome. This paper describes the methods of the NSW Schools Physical Activity and Nutrition Survey 2004 (SPANS 2004).

Mastery of fundamental movement skills among children in New South Wales: prevalence and sociodemographic distribution

Fundamental movement skills form the foundation for many of the specific motor skills employed in popular sports and leisure activities. Little data exist on the prevalence and socioeconomic distribution of fundamental movement skill mastery among young children in Australia. This study process-assessed performance on six fundamental movement skills in a randomly selected sample of students from Years 1 through 3 in the Sydney metropolitan area of New South Wales. The prevalence and sociodemographic distribution of mastery and near mastery for each skill and each skill component is reported for boys and girls in each school year. The findings revealed that the prevalence of mastery and near mastery of each of fundamental movement skill was generally low. Boys performed significantly better than girls in the run and in the four object-control skills (throw, catch, kick, and strike) whilst girls performed better than boys in the skip. There was no consistent association between prevalence of skill mastery and socio-economic status (SES), with only the kick and vertical jump for boys and catch, dodge, and vertical jump for girls differing across SES tertiles. Based on these results, we recommend that adequate curriculum time, resources, and professional development continue to be devoted to fundamental movement skills in NSW primary schools.

Relationship of physical activity to fundamental movement skills among adolescents

PURPOSE

To determine the relationship of participation in organized and nonorganized physical activity with fundamental movement skills among adolescents.

METHODS

Male and female children in Grade 8 (mean age, 13.3 yr) and Grade 10 (mean age, 15.3 yr) were assessed on six fundamental movement skills (run, vertical jump, catch, overhand throw, forehand strike, and kick). Physical activity was assessed using a self-report recall measure where students reported the type, duration, and frequency of participation in organized physical activity and nonorganized physical activity during a usual week.

RESULTS

Multiple regression analysis indicated that fundamental movement skills significantly predicted time in organized physical activity, although the percentage of variance it could explain was small. This prediction was stronger for girls than for boys. Multiple regression analysis showed no relationship between time in nonorganized physical activity and fundamental movement skills.

CONCLUSION

Fundamental movement skills are significantly associated with adolescents' participation in organized physical activity, but predict only a small portion of it.

The reliability and validity of the physical activity questions in the WHO health behaviour in schoolchildren (HBSC) survey: a population study

OBJECTIVE

To assess the test-retest reliability and validity of the physical activity questions in the World Health Organisation health behaviour in schoolchildren (WHO HBSC) survey.

METHODS

In the validity study, the Multistage Fitness Test was administered to a random sample of year 8 (mean age 13.1 years; n = 1072) and year 10 (mean age 15.1 years; n = 954) high school students from New South Wales (Australia) during February/March 1997. The students completed the self report instruments on the same day. An independent sample of year 8 (n = 121) and year 10 (n = 105) students was used in the reliability study. The questionnaire was administered to the same students on two occasions, two weeks apart, and test-retest reliability was assessed. Students were classified as either active or inadequately active on their combined responses to the questionnaire items. Kappa and percentage agreement were assessed for the questionnaire items and for a two category summary measure.

RESULTS

All groups of students (boys and girls in year 8 and year 10) classified as active (regardless of the measure) had significantly higher aerobic fitness than students classified as inadequately active. As a result of highly skewed binomial distributions, values of kappa were much lower than percentage agreement for test-retest reliability of the summary measure. For year 8 boys and girls, percentage agreement was 67% and 70% respectively, and for year 10 boys and girls percentage agreement was 85% and 70% respectively.

CONCLUSIONS

These brief self report questions on participation in vigorous intensity physical activity appear to have acceptable reliability and validity. These instruments need to be tested in other cultures to ensure that the findings are not specific to Australian students. Further refinement of the measures should be considered.