The effect of question order on reporting physical activity and walking behavior.

Background: Question order might affect self-reported regular physical activity (PA) measured with items from the Behavioral Risk Factor Surveillance System (BRFSS) PA module.

Methods: A telephone survey was conducted using 2 forms (N = 1004, N = 212) with varying PA question order. The standard form presented moderate-PA, vigorous-PA, and walking questions, in that order, whereas the alternate form presented walking questions, followed by moderate-PA, and then vigorous-PA questions. Weighted, adjusted rates of vigorous PA, walking, meeting the Centers for Disease Control and Prevention (CDC) recommendation for moderate or vigorous PA, and moderate PA from each form were compared.

Results: Vigorous PA and walking were similar regardless of question order. Meeting the CDC recommendation for moderate or vigorous PA was reported less often with the alternate form among 18- to 34-year-olds. Less moderate PA was reported with the alternate form overall and among 18- to 34-year-olds, women, whites, and those with a high school education or less.

Conclusion: Estimating PA and walking across sociodemographic strata with differing patterns of PA requires asking moderate-PA and vigorous-PA questions before walking questions. Asking walking questions first might lead to bias, especially for moderate PA. Walking, added to a survey with BRFSS moderate and vigorous PA items, should be placed after moderate and vigorous PA. Walking questions first may cause bias, especially for moderate PA.