SLEEPSleep Regularity is a Stronger Predictor of Mortality Risk than Sleep Duration: A Prospective Cohort Study

In 60,977 UK Biobank participants, objectively measured sleep regularity predicted mortality risk over about 6.3 years of follow-up. The finding is observational, but it broadens cardiometabolic prevention conversations beyond sleep duration alone.

Clinical Considerations

• Researchers analyzed more than 10 million hours of accelerometer data using the Sleep Regularity Index.
• Higher sleep regularity was associated with 20%-48% lower all-cause mortality risk versus the least regular quintile.
• More regular sleep also correlated with lower cardiometabolic mortality and cancer mortality in adjusted models.
• Sleep regularity outperformed sleep duration in model comparisons, though causality cannot be established.

Practice Applications

• Recognize sleep timing consistency as a potential marker of cardiometabolic risk.
• Interpret findings cautiously because exposure was measured during one week.
• Consider sleep regularity when discussing lifestyle risk factors with high-risk patients.
• Avoid presenting regular sleep timing as an outcomes-proven intervention.