Published Papers - Abstract 379

Brown WJ, Burton NW, Marshall AL and Miller YD. Reliability and validity of a modified self-administered version of the Active Australia physical activity survey in a sample of mid-age women. Australian and New Zealand Journal of Public Health, 2008; 326: 535-541

Objective: To assess the test-retest reliability and validity of a modified selfadministered version of the Active Australia physical activity survey.Methods: One hundred and fifty-nine mid-age women (54-59 years) completed a mailed physical activity questionnaire before recording daily pedometer step counts for seven consecutive days. A random subsample (n=44) also wore an accelerometer during this period. Participants then completed the physical activity questionnaire again. Spearman’s ? and per cent agreement were used to assess test-retest reliability. Selfreported physical activity data (time 2) were compared with pedometer andaccelerometer data using box plots and Spearman’s correlations to assess validity.Results: Median time between surveys was 13 days. Median frequency and duration of moderate and vigorous physical activity were the same at both surveys, but medianwalking frequency was slightly higher at time 2 than time 1. Reliability coefficients for frequency/time in each domain of physical activity ranged from 0.56-0.64 and percent agreement scores ranged from 40% to 65% for the physical activity categories; agreement was 76% for ‘meeting guidelines’. Correlations (?) between self-reportedphysical activity and 1) weekly pedometer steps and 2) accelerometer data for duration of at least moderate intensity physical activity were 0.43 and 0.52 respectively.Conclusions: The measurement properties of this modified self-administered physical activity survey are similar to those reported for the original computer assisted telephone interview survey.