Plain-English Summary
Sleep Duration Mortality Meta-Analysis studied sleep duration in Adults in prospective cohort studies evaluating sleep duration and all-cause mortality. Compared with 7 hours per day, nighttime sleep duration showed a U-shaped association with all-cause mortality.
Key Findings
- Compared with 7 hours per day, nighttime sleep duration showed a U-shaped association with all-cause mortality.
- For nighttime sleep, reported relative risks versus 7 hours were 1.07 for 4 hours, 1.04 for 5 hours, 1.01 for 6 hours, 1.07 for 8 hours, 1.21 for 9 hours, 1.37 for 10 hours, and 1.55 for 11 hours.
- For 24-hour sleep duration, reported relative risks versus 7 hours were 1.09 for 4 hours, 1.05 for 5 hours, 1.02 for 6 hours, 1.08 for 8 hours, 1.27 for 9 hours, 1.53 for 10 hours, and 1.84 for 11 hours.
- Reverse causality and poor baseline health are major interpretive concerns, especially for long sleep.
Limitations
- Sleep duration was self-reported in nearly all included studies.
- Prospective cohort associations cannot prove causality.
- Residual confounding, changing sleep patterns, and reverse causality remain important concerns.
- Sleep quality, sleep apnea, insomnia, and sleep regularity were not the primary exposure.
Why It Matters
All-cause mortality by reported sleep duration.
Viral Vitalism Verdict
Useful evidence, bounded by design: Sleep duration was self-reported in nearly all included studies.