Measuring physical activity in field studies: Comparison of a questionnaire, 24-hour recall and an accelerometer

Abstract

In a field setting, we compared a physical activity questionnaire (SQUASH), a 24-hour recall measure (Physical Activity Scale; PAS), and an accelerometer to: (1) quantify the amount of time spent in light, moderate, and vigorous physical activity; (2) calculate activity scores; and (3) categorize participants by physical activity tertiles. For 7 consecutive days, 103 participants (61% males, 39% females; mean age 36.8 years, mean body mass index 26.6 kg·m⁻²) wore an accelerometer and completed the PAS. Immediately before these 7 days, the participants completed the SQUASH and underwent anthropometric measurements (weight and height). Time spent in light (r=0.66, Pr=0.76, Pr=0.62, Pr=0.53, Pr=0.62, Pr=0.40, P<0.05). Moderate agreement was observed between tertiles for the accelerometer and PAS activity scores in the overall population (weighted kappa =0.47; 95% confidence interval =0.27–0.67) but not between the accelerometer and SQUASH. In conclusion, a 7-day administration of the PAS is a useful measure for classification of physical activity in the population studied. The SQUASH has practical advantages in terms of convenience of administration, but its usefulness in estimating physical activity is limited.