Table 2.
Pooled HRs and 95% CIs for OS according to subgroup
| Subgroup analysis | No. of patients | No. of studies | Random-effects model | Heterogeneity | ||
|---|---|---|---|---|---|---|
|
| ||||||
| HR (95% CI) | P-value | I2 (%) | P-value | |||
|
| ||||||
| OS | 3,237 | 28 | 1.79 (1.49–2.16) | <0.001 | 67.8 | 0.000 |
| Ethnicity | ||||||
| Asian | 2,687 | 21 | 1.89 (1.56–2.29) | <0.001 | 63.0 | 0.000 |
| Caucasian | 550 | 7 | 1.53 (0.89–2.62) | 0.121 | 77.0 | 0.000 |
| Tumor type | ||||||
| ESC | 712 | 5 | 2.21 (1.74–2.82) | <0.001 | 0 | 0.496 |
| Gastric | 1,012 | 7 | 1.99 (1.58–2.51) | <0.001 | 0 | 0.954 |
| Breast | 386 | 3 | 1.24 (0.94–1.62) | 0.123 | 29.9 | 0.240 |
| Lung | 210 | 2 | 0.89 (0.29–2.71) | 0.841 | 92.2 | 0.000 |
| Colorectal | 195 | 2 | 0.92 (0.20–4.30) | 0.919 | 92.7 | 0.000 |
| Other | 722 | 9 | 2.38 (1.94–2.93) | <0.001 | 0 | 0.990 |
| Tumor source | ||||||
| Digestive system | 2,008 | 15 | 1.89 (1.50–2.38) | <0.001 | 55.1 | 0.005 |
| Urogenital system | 314 | 3 | 2.42 (1.87–3.13) | <0.001 | 0 | 0.766 |
| Other | 915 | 10 | 1.50 (1.09–2.06) | 0.012 | 68.9 | 0.001 |
| Analysis type | ||||||
| Multivariate | 965 | 10 | 2.12 (1.65–2.73) | <0.001 | 40 | 0.091 |
| Univariate | 2,272 | 18 | 1.63 (1.30–2.06) | <0.001 | 70.8 | 0.000 |
| HR acquisition method | ||||||
| Reported | 1,227 | 10 | 1.64 (1.12–2.41) | 0.012 | 75.0 | 0.000 |
| Extrapolated | 2,010 | 18 | 1.88 (1.52–2.33) | <0.001 | 64.0 | 0.000 |
Abbreviations: ESC, esophageal squamous cell carcinoma; OS, overall survival.