Intervention effects on physical activity: the HEIA study - a cluster randomized controlled trial

Abstract

BackgroundAlthough school-based interventions to promote physical activity in adolescents have been suggested in several recent reviews, questions have been raised regarding the effects of the strategies and the methodology applied and for whom the interventions are effective. The aim of the present study was to investigate effects of a school-based intervention program: the HEalth in Adolescents (HEIA) study, on change in physical activity, and furthermore, to explore whether potential effects varied by gender, weight status, initial physical activity level and parental education level.MethodsThis was a cluster randomized controlled 20 month intervention study which included 700 11-year-olds. Main outcome-variable was mean count per minute (cpm) derived from ActiGraph accelerometers (Model 7164/GT1M). Weight and height were measured objectively. Adolescents reported their pubertal status in a questionnaire and parents reported their education level on the consent form. Linear mixed models were used to test intervention effects and to account for the clustering effect of sampling by school.ResultsThe present study showed an intervention effect on overall physical activity at the level of p = 0.05 with a net effect of 50 cpm increase from baseline to post intervention in favour of the intervention group (95% CI −0.4, 100). Subgroup analyses showed that the effect appeared to be more profound among girls (Est 65 cpm, CI 5, 124, p = 0.03) and among participants in the low-activity group (Est 92 cpm, CI 41, 142, p < 0.001), as compared to boys and participants in the high-activity group, respectively. Furthermore, the intervention affected physical activity among the normal weight group more positively than among the overweight, and participants with parents having 13–16 years of education more positively than participants with parents having either a lower or higher number of years of education. The intervention seemed to succeed in reducing time spent sedentary among girls but not among boys.ConclusionsA comprehensive but feasible, multi-component school-based intervention can affect physical activity patterns in adolescents by increasing overall physical activity. This intervention effect seemed to be more profound in girls than boys, low-active adolescents compared to high-active adolescents, participants with normal weight compared to the overweight, and for participants with parents of middle education level as opposed to those with high and low education levels, respectively. An implementation of the HEIA intervention components in the school system may have a beneficial effect on public health by increasing overall physical activity among adolescents and possibly among girls and low-active adolescents in particular.

Effects of a 20-month cluster randomised controlled school-based intervention trial on BMI of school-aged boys and girls: the HEIA study

“…Sufficiently intense intervention (daily expert-led physical education) and adequate duration (1 year) were two strengths that were pointed out in the successful KISS study, which managed to favourably affect estimates of body composition in first and fifth grade schoolchildren 24. Additionally, both the control group and the intervention group in the present study increased their total physical activity significantly during the intervention 15. This was unexpected as a decline in physical activity with increasing age has repeatedly been documented between the ages 9 and 15 25–27.…”

“…Unintentionally, the intervention components may therefore have been better adapted and delivered to girls than to boys. The earlier demonstrated intervention effects on behaviours in girls but not in boys may partly explain why the intervention was effective on BMI and BMIz among girls only 14 15. It is possible that boys did not change their physical activity level as much as girls because of higher baseline values and, consequently, had a smaller potential for change.…”

Longitudinal changes in objectively measured sedentary behaviour and their relationship with adiposity in children and adolescents: systematic review and evidence appraisal

“…From a total of 27 initial potentially eligible papers , a final number of 10 eligible and included papers was obtained for study aim 1 (to identify changes in SB longitudinally) and 3 eligible papers for study aim 2 (associations between changes in SB and changes in adiposity), and the process is described in Fig. a,b.…”

“…Study methodological quality (Table ) for study aim 1 was high: all the 10 eligible papers were rated as ≧70% . For studies reporting change in SB, agreement during the methodological quality assessment was 95% ( k = 0.77) on the 80 items.…”

The Impact of a Community-Based Childhood Obesity Prevention Program on Children’s Physical Activity and Fitness

“…The seven-day measurement time period was used for the present study as it provides reliable (R > 0.76) estimation of children' physical activity levels [33] but this was difficult to implement as only 63% of children had close to 6 days at baseline and 45% had close to 5 days of valid wear time at follow up. A large-scale study found that there was 15% reduction from baseline to follow-up in the number of participants having 5 valid days of accelerometer wear time following a 20-month intervention [34]. Children may not want wear accelerometers due to negative peer pressure, forgetfulness, or discomfort [35].…”