Use of time in chronic obstructive pulmonary disease: Longitudinal associations with symptoms and quality of life using a compositional analysis approach.

Background and objectivesThis study explored whether, for people with chronic obstructive pulmonary disease (COPD), changes to the 24-hour composition of physical activity (PA), sedentary behaviour (SB) and sleep were associated with changes in symptoms and health-related quality of life (HRQoL); and how time re-allocations between these behaviours were associated with changes in outcomes.MethodsThis study pools data on people with COPD drawn from two previous studies: a randomised controlled trial of cognitive behavioural therapy and pulmonary rehabilitation and a usual care cohort. Participants recalled behaviours and completed symptom and HRQoL assessments at baseline (T0) and four months (T1). Linear mixed-effects models (pooled control/intervention samples) predicted changes in outcomes from T0 to T1 with a change to the 24-hour behaviour composition; compositional isotemporal substitution predicted change in outcomes when re-allocating time between behaviours.ResultsValid data were obtained for 95 participants (forced expiratory volume in one second %predicted = 49.6±15.3) at T0 and T1. A change in the 24-hour behaviour composition was associated with a change in anxiety (pConclusionTo improve the overall health and wellbeing of people with COPD, intervention approaches that optimise the composition of PA, SB and sleep may be beneficial.