Measurement of adults' sedentary time in population-based studies

Abstract

Sedentary time (too much sitting) increasingly is being recognized as a distinct health risk behavior. This paper reviews the reliability and validity of self-reported and device-based sedentary time measures and provides recommendations for their use in population-based studies. The focus is on instruments that have been used in free-living, population-based research in adults. Data from the 2003-2006 National Health and Nutrition Examination Survey are utilized to compare the descriptive epidemiology of sedentary time that arises from the use of different sedentary time measures. A key recommendation from this review is that, wherever possible, population-based monitoring of sedentary time should incorporate both self-reported measures (to capture important domain- and behavior-specific sedentary time information) and device-based measures (to measure both total sedentary time and patterns of sedentary time accumulation).

Figure 1

Correlations (r or ρ) of self-reported sitting time assessed by a single-item (circles) or as a composite total (four items or more, triangles) with accelerometer-derived sedentary time Note: Reference lines indicate typical correlations of moderate and vigorous physical activity (interviewer-administered) with accelerometer measures. A * indicates partial correlations, adjusted for age, marital status, white or nonwhite ethnicity, number of children, and highest level of education.

Figure 2

Bland–Altman plot of agreement between activPAL and accelerometer-derived (<100 counts per minute) sedentary time (hours)

Figure 3

Device-based (a) and self-reported (b) measures of sedentary time across age categories in U.S. adults aged ≥20 years (NHANES 2003–2006). Note: Data are reported as mean or prevalence (95% CI) NHANES, National Health and Nutrition Examination Survey

Figure 4

Prevalence (95% CI) of self-reported TV viewing ≥2 hours/day (a,b); computer use ≥1 hour/day (c,d); sitting (e,f) and mean (95% CI) accelerometer-measured sedentary time (g,h) Note: Measured across age categories in U.S. men (a,c,e,g) and women (b,d,f,h) aged ≥20 years by race/ethnicity (NHANES 2003–2006) NHANES,