Table 4.
Results of subgroup and sensitivity analyses.
| Subgroup analyses | No. of studies (cases/samples) | Heterogeneity | Model | Meta-analysis | |||
|---|---|---|---|---|---|---|---|
| I2(%) | p | HR | 95%CI | p | |||
| ADJUSTED COVARIATES | |||||||
| Smoking and alcohol | 3(916/144939) | 0 | 0.95 | Fixed | 1.15 | 0.98-1.35 | 0.09 |
| Smoking, alcohol, and diabetes | 2(717/79041) | 0 | 0.92 | Fixed | 1.17 | 0.97-1.41 | 0.11 |
| SMOKING STATUS | |||||||
| None smokers | 1(222/19933) | NA | NA | NA | 1.38 | 0.93-2.05 | 0.11 |
| STUDY DESIGN | |||||||
| Prospective cohort | 3(916/144939) | 0 | 0.95 | Fixed | 1.15 | 0.98-1.35 | 0.09 |
| Retrospective cohort | 1(188/153566) | NA | NA | NA | 0.93 | 0.70-1.24 | 0.62 |
| GENDER | |||||||
| Male and female | 2(362/184232) | 0 | 0.59 | Fixed | 0.96 | 0.74-1.24 | 0.76 |
| Female | 2(253/136955) | 0 | 0.46 | Fixed | 1.14 | 0.87-1.48 | 0.34 |
| Male | 2(704/122185) | 68 | 0.08 | Random | 1.01 | 0.72-1.41 | 0.95 |
| COUNTRY OF ORIGIN | |||||||
| Asia | 1(188/153566) | NA | NA | NA | 0.93 | 0.70-1.24 | 0.62 |
| Europe | 1(174/30666) | NA | NA | NA | 1.13 | 0.59-2.16 | 0.71 |
| USA | 2(742/114244) | 0 | 0.74 | Fixed | 1.15 | 0.79-1.36 | 0.10 |
| SENSITIVITY ANALYSES | |||||||
| Study with longest follow-up duration omitted | 3(930/267810) | 0 | 0.43 | Fixed | 1.09 | 0.94-1.26 | 0.25 |
| Study with shortest follow-up duration omitted | 3(916/144939) | 0 | 0.95 | Fixed | 1.15 | 0.98-1.35 | 0.09 |
| Co-twin study excluded | 3(930/267810) | 0 | 0.43 | Fixed | 1.09 | 0.94-1.26 | 0.25 |
| Excluded study without adjustment of smoking status | 3(916/144939) | 0 | 0.95 | Fixed | 1.15 | 0.98-1.35 | 0.09 |
CI, confidence interval; HR, hazard ratio; NA, not available.