Psychometric evaluation of an adapted Arabic version of the Global Physical Activity Questionnaire (GPAQ-AR)

Background Accurate assessment of physical activity is crucial for public health surveillance; however, the psychometric properties of the adapted Arabic version of the Global Physical Activity Questionnaire (GPAQ-AR) remain understudied in community-based Egyptian populations, creating a gap in local health monitoring tools. The purpose of this study was to assess the reliability and validity of the GPAQ-AR in Egyptian adults. Methods This cross-sectional validation study with a two-week follow-up included 151 healthy adults (76 males, 75 females) from Egypt. To assess test-retest reliability, the GPAQ-AR was administered on two occasions, two weeks apart. Criterion validity was evaluated by comparing the GPAQ-AR and the International Physical Activity Questionnaire—Short Form (IPAQ-SF) against average daily step counts from a pedometer worn for seven consecutive days. Results The GPAQ-AR showed high test-retest consistency for both males [ r = .840–.991, 95% CI (.758, .994)] and females [ r = .686–.980, 95% CI (.544, .987)]. It demonstrated excellent absolute agreement for total energy expenditure (males: ICC = .933; females: ICC = .898). High convergence was found with the subjective IPAQ-SF for both males [ r = .896, 95% CI (.857, .925)] and females [ r = .907, 95% CI (.872, .933)]. However, its association with objective pedometer data was weak, showing no significant correlation for males [ r = .005, 95% CI (−.155, .164)] and a significant but weak negative correlation for females [ r = −.257, 95% CI (−.398, −.101)]. The GPAQ-AR yielded substantially higher estimates of physical activity volume than could be captured by ambulatory step counts. Conclusions This study provides preliminary evidence that the GPAQ-AR demonstrates high test-retest but shows limited association with objective ambulatory activity. Due to the construct mismatch between total reported energy expenditure and ambulatory steps, the GPAQ-AR is more suitable for ranking individuals' physical activity levels than for determining absolute energy expenditure.