Abstract
Understanding the simultaneous patterning of accelerometer-measured physical activity and sedentary behavior (physical behaviors) can inform targeted interventions. This cross-sectional study described multi-component patterns and correlates of physical behaviors using accelerometry among diverse postmenopausal women. The Women's Health Accelerometry Collaboration combined two United States-based cohorts of postmenopausal women with similar accelerometry protocols and measures. Women (n=22,612) 62 to 97 years enrolled in the Women's Health Study (n=16,742) and the Women's Health Initiative Objective Physical Activity and Cardiovascular Health Study (n=5870) wore an ActiGraph GT3X+ accelerometer on their hip for one week. Awake-time accelerometry data were summarized using the accelerometer activity index into sedentary behavior, light (low, high), and moderate-to-vigorous physical activity. Latent class analysis was used to classify physical behavior hour-by-hour. Five unique patterns were identified with higher total volume of physical activity and lower sedentary behavior with each successively higher-class number based on percentage of the day in physical activity/sedentary behavior per hour over seven days. The percentage assignment was 16.3% class 1, 33.9% class 2, 20.2% class 3, 18.0% class 4, and 11.7% class 5. Median posterior probabilities ranged from 0.99-1.00. Younger age, higher education and general health, normal weight, never smokers, weekly drinking, and faster self-reported walking speed generally had higher class assignment compared to their counterparts. History of diabetes and cardiovascular disease generally had lower class assignment compared to those without these conditions. These results can inform targeted interventions based on common patterns of physical behaviors by time of day among postmenopausal women.