Daily associations between the physical environment and sleep among a diverse, national sample of young adults.
Level 3 - non-randomized controlled study
Prospective longitudinal observational study with multilevel modeling
PubMed 42637624 · doi:10.1016/j.sleh.2026.07.010
What was done
Young adults in the Future of Families "Young Adult Sleep Study" (n = 372; 60% female) wore wrist-actigraphs and completed daily self-report diaries for two weeks. Participants reported whether three physical sleep environment factors (temperature, light, and noise) disrupted their sleep each night. Multilevel models were used to examine between-person and within-person associations of these factors with actigraphic sleep timing, duration, wake after sleep onset (WASO), sleep maintenance efficiency, and self-reported sleep quality.
What was found
Between-person findings: - A "too hot" environment was associated with greater WASO (b = 9.93 minutes, 95% CI [3.64, 16.21], P = .006) and reduced sleep maintenance efficiency (b = -1.78%, 95% CI [-3.01, -0.54], P = .010). - "Too noisy inside" was associated with lower sleep maintenance efficiency (b = -2.97%, 95% CI [-5.24, -0.70], P = .03) and 88% decreased odds of good sleep quality (OR = 0.12, 95% CI [0.02, 0.54], P = .006). - A "too bright" environment was associated with 90% decreased odds of good sleep quality (OR = 0.10, 95% CI [0.01, 0.61], P = .010), later sleep onset (b = 111.05 minutes, 95% CI [26.67, 195.42], P = .010), midpoint (b = 122.95 minutes, 95% CI [41.22, 204.69], P = .010), and offset (b = 131.54 minutes, 95% CI [39.7, 223.40], P = .010). Within-person findings: - A "too hot" night was associated with lower sleep maintenance efficiency (b = -0.79%, 95% CI [-1.13, -0.45], P < .001) and 45% decreased odds of good sleep quality (OR = 0.55, 95% CI [0.39, 0.79], P = .001). - Environmental factors were not associated with actigraphic sleep duration.
Why it matters
This study provides naturalistic evidence linking daily perceived environmental disruptions (heat, light, and noise) to objective delays in sleep timing and lower sleep efficiency among young adults.
Limits
Environmental exposures were measured through retrospective daily self-reports rather than objective physical sensors (e.g., decibel meters, lux meters, or ambient thermometers), which introduces potential reporting bias or reverse causality (poor sleep leading to higher sensitivity to environmental cues). The sample was restricted to young adults monitored for two weeks, limiting generalizability to other age demographics or seasonal variations.
Cited by
- supports Sleep studies show that the ideal sleeping environment is quiet, dark, and cold.