A cluster analysis of patterns of objectively measured physical activity in Hong Kong

Objective The health benefits of exercise are clear. In targeting interventions it would be valuable to know whether characteristic patterns of physical activity (PA) are associated with particular population subgroups. The present study used cluster analysis to identify characteristic hourly PA patterns measured by accelerometer. Design Cross-sectional design. Setting Objectively measured PA in Hong Kong adults. Subjects Four-day accelerometer data were collected during 2009 to 2011 for 1714 participants in Hong Kong (mean age 44·2 years, 45·9 % male). Results Two clusters were identified, one more active than the other. The 'active cluster' (n 480) was characterized by a routine PA pattern on weekdays and a more active and varied pattern on weekends; the other, the 'less active cluster' (n 1234), by a consistently low PA pattern on both weekdays and weekends with little variation from day to day. Demographic, lifestyle, PA level and health characteristics of the two clusters were compared. They differed in age, sex, smoking, income and level of PA required at work. The odds of having any chronic health conditions was lower for the active group (adjusted OR = 0·62, 95 % CI 0·46, 0·84) but the two groups did not differ in terms of specific chronic health conditions or obesity. Conclusions Implications are drawn for targeting exercise promotion programmes at the population level.