Monitoring sleep duration, timing, and continuity among US youth and adults in NHANES using actigraphy

Sleep health differs across the life course and by sex, poverty-income ratio (PIR), and race and ethnicity. Monitoring sleep is important for informing interventions to improve sleep heath. Our objective was to explore and describe sleep characteristics among a nationally-representative US sample by age, sex, PIR, and race and ethnicity.

Data came from n=13,656 US residents aged 3-80 years in the National Health and Nutrition Examination Survey (2011-2014). Participants wore an ActiGraph GT3X+ on their wrist for ≤7 days to assess sleep. We used GGIR (v. 3.0.0) to derive sleep duration, sleep onset, sleep midpoint, waketime, wake after sleep onset (WASO), and social jetlag. Participant characteristics were self-reported. Statistical analyses were performed using SAS v. 9.4 (SAS Institute Inc., Cary, NC) and accounted for complex sampling designs. We used Time-Varying Effect Models to model sleep by age.

Sleep duration was shorter with greater age. Sleep onset, midpoint, and waketime were latest among those aged 10-30 years. Social jetlag followed a similar distribution. WASO was highest among children and was lower with greater age. Females generally slept more than males. Adults with low PIR tended to have worse sleep compared with adults with higher PIR. Compared with Non-Hispanic White adults, Hispanic, Non-Hispanic Asian, and Non-Hispanic Black adults had shorter sleep duration and higher WASO. Non-Hispanic Black adults had the highest social jetlag.

We described sleep health in the US, including relevant population subgroups. These findings may help prioritize public health interventions to improve sleep health.