Validity of the active Australia survey in an Australian cardiac rehabilitation population

Objective To examine the long-term validity of the Active Australia Survey (AAS) in a cardiac rehabilitation population using accelerometry as the reference measure. Design Cohort validation study. Methods Cardiac rehabilitation participants with coronary heart disease were recruited to a prospective cohort study. Over 7-days, 61 participants wore an ActiGraph ActiSleep accelerometer (1-s epoch, 10-min bout) and completed the self-administered AAS at baseline, 6-weeks, 6 and 12-months. Total daily moderate-to-vigorous physical activity (MVPA) from both methods were compared using Bland–Altman plots and Spearman rank-order correlations. Results Participants tended to over-report MVPA, with more active participants more likely to over-report MVPA. There was a good level of agreement between the accelerometer 1-s epochs and AAS at all time points (mean bias between accelerometer 1-s epochs and AAS (ratio) 1.04, 1.16, 1.14, and 1.06, respectively), with weak-moderate correlations (ρ = 0.3–0.48). Conversely, there was a poor level of agreement between the accelerometer 10-min bouts and AAS at all time points (mean bias between accelerometer 10-min bouts and AAS (ratio) 6.78, 9.09, 6.35, and 5.68, respectively), with weak-moderate correlations (ρ = 0.3–0.52). Agreement between the two measures did not improve over time for both 1-s and 10-min bout accelerometry data. Conclusions The AAS may be an acceptable self-report measure of MVPA in cardiac rehabilitation attendees when capturing any time spent in MVPA. The AAS may be useful to routinely monitor physical activity levels over-time in Australian cardiac rehabilitation programs at both an individual and group level. Trial registration Trial registration: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12615000995572, http://www.ANZCTR.org.au/ACTRN12615000995572.aspx