Validity of the Active Australia Survey in an Australian cardiac rehabilitation population

Objectives: To examine the long-term validity of the Active Australia Survey 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-second epoch, 10-minute bout) and completed the self-administered Active Australia Survey at baseline, 6-weeks, 6 and 12-months. Total daily moderate-to-vigorous physical activity from both methods was compared using Bland-Altman plots and Spearman rank-order correlations. Results: Participants tended to over-report moderate-to-vigorous physical activity, with more active participants more likely to over-report moderate-to-vigorous physical activity. There was a good level of agreement between the accelerometer 1-second epochs and Active Australia Survey at all time points (mean bias (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-minute bouts and Active Australia Survey at all time points (mean bias (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-second and 10-minute bout accelerometry data. Conclusions: The Active Australia Survey may be an acceptable self-report measure of moderate-to-vigorous physical activity in cardiac rehabilitation attendees when capturing any time spent in moderate-to-vigorous physical activity. The Active Australia Survey may be useful to routinely monitor physical activity levels over-time in Australian cardiac rehabilitation programs at both individual and group levels. Trial registration: Trial registration: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12615000995572, http://www.ANZCTR.org.au/ACTRN12615000995572.aspx.