Criterion Validity of Commonly Used Sedentary Behavior Questionnaires to Measure Total Sedentary Time in Adults

Background: Self-report questionnaires are a fast and cost-efficient method to determine habitual sedentary time (sitting/lying time while awake), but their accuracy versus thigh-worn accelerometry (criterion), which can distinguish between sitting and standing postures, is unclear. While the validity of sedentary questionnaires has previously been evaluated, they have not been investigated simultaneously in the same sample population. We tested the hypothesis that common sedentary questionnaires underpredict habitual sedentary time compared with an objective, monitor-based assessment. Methods: Ninety-three participants (30 +/- 18 years, 59 females) wore the activPAL inclinometer on the midthigh 24 hr per day for 6.9 +/- 0.4 days and completed the SIT-Q, Sedentary Behavior Questionnaire (SBQ), International Physical Activity Questionnaire (IPAQ), and Physical Activity and Sedentary Behavior Questionnaire (PASB-Q). Results: In comparison to the activPAL (9.9 +/- 1.9 hr/day), the SIT-Q measured more time (12.9 +/- 5.4 hr/day), but the SBQ (7.5 +/- 3.3 hr/day), IPAQ (7.4 +/- 3.0 hr/day), and PASB-Q (6.6 +/- 3.0 hr/day) measured less time (all p < .001). The SIT-Q was positively and weakly correlated (rho = .230 [95% confidence interval: .020, .422], p = .028) with the activPAL, but the SBQ, IPAQ, and PASB-Q were not (all ps > .760). Equivalence testing demonstrated poor equivalence for the SIT-Q (+/- 40%), SBQ (+/- 31%), IPAQ (+/- 36%), and PASB-Q (+/- 29%). The SIT-Q (beta = -1.36), SBQ (beta = -0.97), and IPAQ (beta = -0.78) exhibited a negative proportional bias (all ps < .002). Conclusions: In summary, the SIT-Q, SBQ, IPAQ, and PASB-Q demonstrated poor validity. Researchers and health promoters should be cautious when implementing these self-report sedentary time questionnaires, as they may not reflect the true sedentary activity and negatively impact study results.