Table 7.
Subgroup analysis for disease-specific survival
| No. of included articles | No. of cases | Pooled HR (95 % CI) | Chi2 (p value) | I2 | Ph* | |
|---|---|---|---|---|---|---|
| Publication year | 0.0517 | |||||
| 2003–2010 | 4 | 375 | 1.61 (1.09–2.38) | 7.42 (0.06) | 60 % | |
| 2011–2014 | 6 | 2591 | 1.51 (1.16–1.97) | 12.22 (0.03) | 59 % | |
| Region | 0.3206 | |||||
| USA | 3 | 1979 | 1.57 (1.10–2.22) | 11.45 (0.003) | 83 % | |
| Europe | 5 | 1679 | 1.54 (1.02–2.31) | 14.19 (0.007) | 72 % | |
| Asia | 2 | 261 | 1.61 (1.08–2.39) | 0.46 (0.5) | 0 % | |
| No. of patients | 0.0015 | |||||
| <100 | 5 | 331 | 1.40 (0.82–2.40) | 12.35 (0.01) | 68 % | |
| ≥100 | 5 | 2635 | 1.55 (1.23–1.95) | 14.06 (0.007) | 72 % | |
| Median follow-up* | 0.0017 | |||||
| <36 months | 4 | 1643 | 1.85 (1.53–2.24) | 2.58 (0.46) | 0 % | |
| ≥36 months | 5 | 544 | 1.20 (0.91–1.59) | 7.43 (0.11) | 46 % | |
| Analysis results | 0.1626 | |||||
| Not significant | 4 | 382 | 1.14 (0.69–1.87) | 7.37 (0.06) | 59 % | |
| Significant | 6 | 2584 | 1.69 (1.31–2.17) | 18.98 (0.002) | 74 % | |
| Quality scale | 0.0233 | |||||
| ≤4 | 7 | 2361 | 1.60 (1.26–2.03) | 16.99 (0.009) | 65 % | |
| >4 | 3 | 605 | 1.08 (0.51–2.30) | 8.91 (0.01) | 78 % |
HR: hazard ratio, CI: confidence interval
Ph* for heterogeneity between subgroups with meta-regression analysis
*One study was excluded because the duration of follow-up was not available (Morgan [26])