Evaluation of the reliability and validity of Azad-Fesharaki's physical activity questionnaire (AFPAQ)

Noticing the importance of measuring physical activity in medical investigations, this study was conducted to analyze the validity and reliability of the researcher-made Physical Activity Questionnaire (AFPAQ) of Azad and Fesharaki, so as to achieve a suitable tool. In this cross-sectional study, the sample population all army men selected through two-stage cluster sampling according to Morgan samples table. After investigating content validity, confirmatory and explanatory factor analysis, Pearson correlation (using general health questionnaire (GHQ) and test-retest coefficient were used to examine construct and predictive validity, respectively. Data analysis was done using SPSS software version 15 and Amos version 16. This study was done on 724 subjects including 54 (7.3%) women and 685 (92.7%) men. The CVR coefficient was 60% for this study. Also, explanatory factor analysis showed three factors, including physical activity at work, physical activity at leisure time, and exhaustion with 45% total variance and 71% Kaser-Meyer-Olkin Index. These factors were also confirmed by confirmatory factor analysis (AGFI=0.963, RMSEA=0.053). The reliability of the questionnaire was %40 and %70 using Cronbach's Alpha and test-re-test method, respectively. Since validity and reliability indexes of the questionnaire were reported desirable, AFPAQ can be considered a valid and reliable questionnaire for measuring physical activity.