0277 Improving the Validity of Self-Reported Sleep Duration: Experimental Comparisons of Question Format with Actigraphy

Abstract Introduction Accurate measurement of sleep is a challenge for researchers and practitioners. Objective measures (i.e., polysomnography, actigraphy) are expensive time-consuming. Thus, the practical approach self-report – with cost reduced validity. The purpose this actigraphy ­experiment was to compare validity differently ­formatted self-reported duration measures. It hypothesized that question formats which encourage reporting nearest 15 minutes would lead improved Methods Adults (n=56, 73.2% female, 80.4% white, mean age = 21.3 years, SD 4.18) were recruited through university email, psychology participant pool, word mouth. Sleep recorded via 7 days. Participants randomly assigned respond computer one three versions Pittsburgh Quality Index (Buysse et al., 1989). Specifically, they reported hours per night in following formats: 1) Open-ended response standard instructions 2) modified “round 15-minutes”, or 3) Standard drop-down menus select (15-minute increments). Results Self-reported strongly correlated, r .63, p < .001. Average (7.05 hours) significantly longer than average (M 6.65 hours), t(55) 3.27, .01, d 0.44. There no significant differences across formats, F(2, 53) 0.02, .98, η2 .00. As expected, open-ended format had weakest correlation (r .47), whereas .74) menu .68) better predictors duration. effect sizes improvement (q .44, .32) medium magnitude (Cohen, 1969). Conclusion results suggest practitioners should consider questions. We found participants more precise estimates predict actigraphy. Additional data needed replicate these findings, understanding factors influence agreement between objective subjectively Support (if any)