Single versus multiple item questions on occupational physical activity

In 2002, the National Physical Activity and Weight Loss Survey asked two sets of questions on occupational physical activity—one question from the Behavioral Risk Factor Surveillance System (BRFSS) and eight detailed questions from the occupational physical activity questionnaire (OPAQ). This study compares the responses. Methods: On the basis of percentage of occupational physical activity reported on OPAQ, 5847 respondents were classified by three levels (sitting or standing, walking, and heavy labor). Kappa, MET-min per day, and median hours worked at the three levels were calculated to compare the two sets of questions. Results: Levels of occupational physical activity reported on the BRFSS question agreed with OPAQ (kappa = 0.56). Hours of heavy labor per day reported on OPAQ increased among the three activity levels on BRFSS. Conclusions: The BRFSS question and OPAQ classify respondents similarly by occupational physical activity. The BRFSS question is useful for overview and OPAQ, for more detailed analyse