Group | Number of qualified studies | Short sleep duration | Long sleep duration | ||
---|---|---|---|---|---|
HR (95% CI); P | I2 | HR (95% CI); P | I2 | ||
Overall analyses | |||||
 Mortality (unadjusted) | 23/26 | 1.15 (1.06–1.25); <.001 | 71.5% | 1.43 (1.30–1.58); <.001 | 88.6% |
 Mortality (adjusted) | 32/36 | 1.04 (1.00–1.09); .033 | 16.1% | 1.24 (1.16–1.33); <.001 | 76.2% |
Subgroup analyses based on adjusted mortality | |||||
By gender | |||||
 Both genders | 20/23 | 1.04 (0.99–1.08); .096 | 11.1% | 1.20 (1.11–1.29); <.001 | 79.0% |
 Men | 8/8 | 1.13 (1.04–1.24); .007 | 0.0% | 1.31 (1.10–1.58); .003 | 62.3% |
 Women | 8/9 | 1.00 (0.85–1.18); .999 | 58.6% | 1.48 (1.18–1.86); .001 | 80.4% |
By country | |||||
 America | 12/13 | 1.08 (1.03–1.14); .002 | 0.0% | 1.19 (1.07–1.31); .001 | 78.2% |
 Europe | 6/7 | 1.03 (0.93–1.14); .627 | 0.0% | 1.01 (0.93–1.09); .823 | 0.0% |
 Asia | 14/16 | 1.04 (0.96–1.12); .384 | 40.6% | 1.41 (1.26–1.57); <.001 | 75.4% |
By total sleep time | |||||
 Nighttime | 19/23 | 1.05 (0.99–1.13); .113 | 17.8% | 1.25 (1.13–1.38); <.001 | 73.7% |
 24 h | 13/13 | 1.04 (0.99–1.10); .146 | 19.9% | 1.25 (1.14–1.36); <.001 | 76.2% |
By ascertainment of sleep | |||||
 Questionnaire | 30/34 | 1.04 (1.00–1.09); .055 | 20.5% | 1.26 (1.17–1.35); <.001 | 76.8% |
 Actigraphy | 1/1 | 1.12 (0.89–1.42); .342 | ─* | 0.83 (0.61–1.13); .233 | ─ |
 Both | 1/1 | 1.12 (0.75–1.68); .582 | ─ | 1.24 (0.73–2.10); .425 | ─ |
By follow-up (years) | |||||
  ≥ 7.5 | 20/22 | 1.07 (1.02–1.12); .006 | 15.2% | 1.24 (1.14–1.34); <.001 | 80.2% |
  < 7.5 | 13/14 | 0.99 (0.93–1.05); .736 | 0.0% | 1.27 (1.12–1.45); <.001 | 68.3% |
By age | |||||
  < 65 | 11/11 | 1.21 (1.02–1.23); .018 | 18.2% | 1.38 (1.19–1.60); <.001 | 61.5% |
  ≥ 65 | 21/25 | 1.03 (0.99–1.07); .193 | 4.2% | 1.20 (1.11–1.30); <.001 | 78.2% |
Dose-analysis | |||||
  ≤ 5 h | 15 | 1.06 (1.01–1.11); .014 | 12.3% | ─ | ─ |
  ≤ 6 h | 27 | 1.05 (1.01–1.10); .031 | 26.7% | ─ | ─ |
  ≤ 7 h | 32 | 1.04 (1.00–1.09); .033 | 16.1% | ─ | ─ |
  ≥ 8 h | 33 | ─ | ─ | 1.24 (1.16–1.33); <.001 | 77.9% |
  ≥ 9 h | 26 | ─ | ─ | 1.31 (1.21–1.41); <.001 | 71.9% |
  ≥ 10 h | 10 | ─ | ─ | 1.45 (1.24–1.70); <.001 | 82.6% |