Socioecological approach for identifying the determinants of objectively measured physical activity: A prospective study of the UK Biobank.

The socioecological approach emphasises that health promotion should focus on a variety of factors that surround individuals simultaneously, yet there is little evidence on how these factors relatively affect physical activity (PA). The main objective was to identify relevant determinants of PA by examining the associations between factors within multilayered socioecological categories and PA. A prospective analysis was conducted with 84,052 participants participating in the accelerometer measurement from the UK Biobank. Time spent in moderate-to-vigorous PA (MVPA) was calculated from participants who wore a wrist-worn accelerometer for seven days; a questionnaire-based self-reported leisure-time physical activity was also assessed. A categorical principal component analysis was conducted to reduce the dimensions of 184 variables. The associations between principal components (PCs) and PA were evaluated using general linear models. A network of PCs was constructed to assess the comprehensive association with PA. PCs related to body composition and chronic diseases were suggested as key determinants of objectively measured MVPA and found to be clustered in the network. PCs related to body composition and socio-economic status were proposed as the key regulatory hubs in the network because they exhibited the highest level of indirect linkages with other components. In the environmental category, PCs related to greenness and air pollution were revealed to be key factors in the self-reported walking for pleasure. Using a socioecological approach, it was discovered that obesity and disease-related factors were the most important determinants, and they had an integrative influence with other factors in different categories.