A compositional analysis of time spent in physical activity, sedentary behaviour and sleep with quality of life in Canadian older adults aged 65 years and above: Findings from the Canadian Longitudinal Study on Aging.

Associations between daily time spent in physical activity (PA), sedentary behaviour (SB) and sleep (collectively referred to as 'movement behaviour') and quality of life (QOL) are typically studied without considering they are compositional, co-dependant variables. Study objectives were to use compositional data analysis to: 1) examine the relationship between movement behaviour composition and QOL, 2) estimate the degree to which changing time spent in any movement behaviour within the movement behaviour composition is associated with QOL. 7,918 older Canadian adults ≥ 65 years of age from the Canadian Longitudinal Study on Aging were studied using a quasi-longitudinal study design. Daily time spent in PA and SB were derived from self-reported Physical Activity Scale for the Elderly responses. Nighttime sleep was self-reported separately. QOL was assessed through the Satisfaction with Life Scale. Movement behaviour composition was significantly associated with QOL. Relative time spent in SB was negatively associated with QOL [HR = 0.89 (95% CI: 0.86, 0.93)]. Relative time spent in sleep was positively associated with QOL [HR = 1.10 (95% CI: 1.05, 1.16)]. Time displacement estimates revealed that greatest change in QOL occurred when time spent in PA was decreased and replaced with SB [HR = 0.96 (95% CI: 0.92, 0.99) for 45 min/day displacement]. Using compositional data analysis is advantageous because it shows how reduction in SB and increase in PA and sleep can lead to improvements in QOL for older Canadian adults.