Subgroup | No. of studies | No. of subjects | OR (95%CI) | Heterogeneity | P value | |
---|---|---|---|---|---|---|
I2(%) | P value | |||||
Year of publication | ||||||
 1997 ~  2010 | 10 | 166,949 | 2.53 (1.75 3.66) | 76.8 | <  0.001 | <  0.001 |
 2010 ~  2019 | 8 | 31,944 | 2.10 (0.80 5.53) | 99.5 | <  0.001 | 0.134 |
Study design | ||||||
 Retrospective | 6 | 171,176 | 1.79 (1.33 2.42) | 83.1 | <  0.001 | <  0.001 |
 Prospective | 6 | 4856 | 2.25 (1.39 3.64) | 75.3 | 0.001 | 0.001 |
 Cross-sectional | 6 | 22,861 | 2.45 (0.79 7.61) | 98.9 | <  0.001 | 0.122 |
Sample size | ||||||
 < 1000 | 11 | 2234 | 2.99 (1.28 6.98) | 99.2 | <  0.001 | 0.011 |
 > 1000 | 7 | 196,659 | 1.50 (1.24 1.81) | 53.8 | 0.043 | <  0.001 |
Age of subjects | ||||||
 Mean < 40 | 12 | 189,712 | 2.75 (1.26 6.03) | 99.4 | <  0.001 | 0.011 |
 Mean > 40 | 6 | 9181 | 1.81 (1.30 2.51) | 73.4 | 0.002 | <  0.001 |
Diagnostic criteria | ||||||
 ICD-10 | 2 | 1541 | 2.13 (1.10 4.12) | 43.2 | 0.185 | 0.025 |
 DSM-III-R | 4 | 2681 | 4.80 (2.90 7.67) | 0 | 0.720 | <  0.001 |
 DSM-IV | 11 | 174,541 | 2.11 (0.96 4.65) | 99.4 | <  0.001 | 0.063 |
 CES-D | 1 | 20,130 | 1.12 (0.92 1.37) | – | – | 0.265 |
Diagnostic outcome | ||||||
 Major depression | 12 | 5336 | 2.92(1.42 5.98) | 97.5 | <  0.001 | 0.003 |
 Depression | 6 | 193,557 | 1.41(1.14 1.73) | 75.6 | 0.001 | 0.001 |
Sleep disorder type | ||||||
 Insomnia | 12 | 172,759 | 2.29 (1.69 3.10) | 86.1 | <  0.001 | <  0.001 |
 Nightmares | 3 | 582 | 4.47 (2.00 9.97) | 0 | 0.490 | <  0.001 |
 Hypersomnia | 3 | 2914 | 2.19 (0.77 6.21) | 93.0 | <  0.001 | 0.140 |
 Other | 7 | 27,144 | 2.41 (0.80 7.24) | 99.6 | <  0.001 | 0.117 |
Suicidal behavior type | ||||||
 Suicidal ideation | 13 | 194,419 | 2.32 (1.11 4.88) | 99.2 | <  0.001 | 0.026 |
 Suicide attempts | 7 | 193,834 | 2.41 (1.45 4.02) | 87.7 | <  0.001 | 0.001 |
 Completed suicide | 2 | 163,668 | 1.24 (1.00 1.53) | 0 | 0.445 | 0.050 |
 Other | 2 | 225 | 4.19 (2.82 6.21) | 0 | 0.654 | <  0.001 |