P128 Sleep Need is more Strongly Associated with Self-rated Health and Daytime Function than Sleep Duration

Abstract

Abstract Introduction Most studies examining associations between sleep and health outcomes focus on sleep duration or efficiency, ignoring individual differences in sleep need. We investigated whether sleep need is a more influential correlate of self-rated daytime function and health than sleep duration. Methods This study is a secondary analysis of the 2019 Sleep Health Foundation online survey of adult Australians (N=2,044, aged 18–90 years). Hierarchical multiple linear regressions assessed variance explained by demographics (Model 1: age, sex, BMI), self-reported sleep duration (Model 2: Model 1 + weighted variable of weekday/weekend sleep duration), and individual sleep need (Model 3: Model 2+ how often they get enough sleep to feel their best the next day, on a 5-point scale) on daytime function items for fatigue, concentration, motivation, and overall self-rated health (EQ-5D, VAS 0–100). Results Sleep need explained an additional 17.5–18.7% of the variance in fatigue, concentration, motivation, and health rating (all p < 0.001 for R² change) in Model 3. Model 2 showed that sleep duration alone only explained 2.0–4.1% of the variance in these outcomes. Findings were similar when stratified by sex. Sleep need also explained greater variance for older adults than for younger and middle-aged adults, especially on health rating (Model 3: R² change = 0.11 for ages 18-24y, 0.14 for 45-54y, 0.27 for 75y+). Conclusions Sleep need explains more variance in daytime function and self-rated health than sleep duration. The role of sleep need on other daytime consequences, and in clinical populations, needs further exploration.