861. Community-wide intervention and population-level physical activity: a 5-year cluster randomized trial.
Source: International Journal of Epidemiology
Commentary by: Professor Adrian Bauman, Co-Director GlobalPANet, Professor of Public Health at Sydney University
The paper by Kamada (2017) and colleagues reports on the effectiveness of a community-wide physical activity intervention for mid-aged adults with five years of follow-up. The program ran in 12 districts in Unnan, Japan, and was evaluated using a cluster randomised controlled trial design. The evaluation reported data from more than 1000 adults in each community, with mean ages around 60 years, and roughly similar numbers by gender. This paper is unusual in that it combines community-wide health promotion as intervention elements with the rigorous epidemiological design. This design enhances the internal validity of the findings, and its community-wide setting contributes to external validity. The intervention comprised information provision, structured programs, and a supportive infrastructure targeting aerobic activities, flexibility and muscle strengthening or both. The program was supported by community-based social marketing at the local level.
The results showed small but significant increases in physical activity in the intervention compared to control communities, particularly when aerobic activities alone or flexibility/muscle strengthening alone were the primary intervention. Combining these into a more comprehensive program did not produce a significant effect. The effect size was around a 5 to 6% increase in the proportion meeting physical activity recommendations or meeting muscle strengthening frequency recommendations. Interestingly, the effects were smaller at one year following the intervention, but increased by five years of follow-up.
This program shows that quality evaluation can occur even in community settings, and that sustained but small population effects can be achieved, likely to produce longer term health benefits. Limitations include self-report questionnaires, although these were validated, and showed effects in this true experimental design. Further work in this kind of research could examine implementation, program delivery fidelity, and dose-response relationships between the amount of intervention received and population changes. Nonetheless these data do point to the effectiveness of this physical activity program for middle aged Japanese adults. Well-designed experimental studies at the population level like this are rare, but needed for advancing the physical activity intervention evidence base.
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