Abstract P427: Validity of the Aerobic Physical Activity Questions in the Behavioral Risk Factor Surveillance System
OBJECTIVE: Physical activity provides health benefits for cardiovascular disease and its risk factors. Surveillance of physical activity in U.S. adults informs national health objectives via self-report questionnaires, although the 2011 lack information on validity. This study examines the criterion validity of the aerobic physical activity questions used in the Behavioral Risk Factor Surveillance System (BRFSS).
METHODS: Participants answered the current BRFSS physical activity questions (8 questions total) on the frequency and duration of participation in their two most frequent aerobic physical activities during an in-person interview. Responses to the questions were compared to two validation standards: (1) non-occupational physical activity and exercise abstracted from diaries; and (2) physical activity derived from accelerometers (CSA model 7164 WAM). All measures were summarized as moderate- to vigorous-intensity physical activity (minutes/week). Criterion validity was assessed by comparing questionnaire responses to each validation standard (diary and accelerometer) using the Spearman correlation, mean difference in activity estimates, Kappa coefficient, and percent positive agreement.
RESULTS: Participants in the study were 107 African- American and 122 Hispanic women 40 - 70 years of age with a mean age of 49.3 ± 7.1 years and a mean BMI of 30.0 ± 6.5 kg/m2. Most (85.9%) women completed high-school. Associations between self-reported physical activity, diary reports, and accelerometer counts are shown in the Table.
CONCLUSION: In this sample, based on Spearman correlations >0.30 and fair to moderate Kappa coefficients, the BRFSS aerobic physical activity questions show acceptable validity. Additional studies may be warranted to validate the current BRFSS physical activity questions in samples representative of the age, sex, and racial/ethnic distribution of U.S. adults.
- © 2013 by American Heart Association, Inc.