Table 3. Subgroup analyses of pooled HRs for overall survival.
| Study | No. | HR (95% CI) | Z | p-value | I-squared (%) | p-value | |
|---|---|---|---|---|---|---|---|
| Publication year | |||||||
| 2004–2014 | 6 | 1.782 (1.243–2.064) | 3.15 | 0.002 | 52.0 | 0.064 | |
| 2015–2016 | 7 | 1.727 (1.394–2.141) | 4.99 | 0.000 | 59.1 | 0.023 | |
| Country | |||||||
| Asia | 5 | 1.815 (1.211–2.720) | 2.89 | 0.004 | 76.9 | 0.000 | |
| Europe | 1 | 2.012 (1.159–3.492) | 2.48 | 0.013 | - | - | |
| America | 7 | 1.605 (1.331–1.937) | 4.94 | 0.000 | 23.7 | 0.248 | |
| Case number | |||||||
| <500 | 9 | 1.822 (1.549–2.286) | 6.36 | 0.000 | 0.0 | 0.805 | |
| >500 | 4 | 1.537 (1.097–2.154) | 2.50 | 0.013 | 85.2 | 0.000 | |
| Category | |||||||
| Ovarian cancer | 3 | 1.823 (1.372–2.423) | 4.14 | 0.000 | 0.0 | 0.692 | |
| Epithelial ovarian cancer | 6 | 1.697 (1.298–2.217) | 3.87 | 0.000 | 67.6 | 0.009 | |
| Advanced epithelial ovarian cancer | 3 | 2.359 (1.403–3.968) | 3.24 | 0.001 | 20.1 | 0.286 | |
| High-grade serous ovarian cancer | 1 | 1.220 (0.946–1.573) | 1.53 | 0.125 | - | - | |
| FIGO stage | |||||||
| I–IV | 9 | 1.733 (1.430–2.100) | 5.61 | 0.000 | 50.9 | 0.038 | |
| III–IV | 4 | 1.886 (1.117–3.186) | 2.37 | 0.018 | 63.8 | 0.040 | |
| Cut-off | |||||||
| >300 | 1 | 1.671 (1.314–2.127) | 1.97 | 0.049 | - | - | |
| >350 | 2 | 1.710 (1.170–2.500) | 2.77 | 0.006 | 0.0 | 0.479 | |
| >400 | 7 | 2.070 (1.775–2.413) | 9.29 | 0.000 | 0.0 | 0.455 | |
| >450 | 3 | 1.292 (1.031–1.618) | 2.23 | 0.026 | 34.6 | 0.217 | |
| Cut-off* | |||||||
| >300 | 1 | 1.640 (1.003–2.682) | 1.97 | 0.049 | - | - | |
| >350 | 1 | 1.550 (0.971–2.473) | 1.84 | 0.066 | - | - | |
| >400 | 5 | 2.043 (1.744–2.395) | 8.83 | 0.000 | 0.0 | 0.558 | |
| >450 | 2 | 1.450 (0.876–2.403) | 1.44 | 0.149 | 65.9 | 0.087 | |
CI, confidence interval; FIGO, International Federation of Gynecology and Obstetrics; HR, hazard ratio.
*Only for I–IV patients.