Do adults with cardiovascular disease risk show meaningful reactivity to physical activity measurement? Coordinated analysis across six studies

Abstract

Objectives: To estimate the extent of physical activity (PA) measurement reactivity among adults ages 40–60 with risk factors for cardiovascular disease (CVD), to inform best practices for addressing reactivity in PA research and intervention. Design: Coordinated secondary analysis across six datasets from studies that used 6–7 days of observation following the introduction of PA measurement devices. Moderators of interest were demographic and study design characteristics. Methods: We included data from participants ages 40–60 with ≥1 CVD factors who provided device-assessed PA behaviour across 6–7 days (N = 1825). We used multilevel modelling to examine participants' PA behaviour (i.e., activity units, steps per day) across days, with decreases in activity indicating reactivity. The threshold for statistical significance was set at p