Table 4. Result of meta-analysis and subgroup analysis of overall survival.
| Variables | N (study)a | N (case)b | Pooled data | Heterogeneity | |||
|---|---|---|---|---|---|---|---|
| HR (95% CI) | P | I2 (%) | Ph | ||||
| Overall (CPFE vs. non-CPFE) | 11 | 6,413 | 2.006 (1.347, 2.986) | 0.001 | 85.6 | 0.001 | |
| By analysis method | |||||||
| Univariate | 4 | 1,370 | 1.148 (0.42, 3.173) | 0.788 | 92.5 | <0.001 | |
| Multivariate | 7 | 5,043 | 2.615 (1.672, 4.091) | 0.001 | 79.4 | <0.001 | |
| By sample size | |||||||
| <500 | 7 | 3,449 | 1.976 (1.059, 3.69) | 0.032 | 84 | <0.001 | |
| ≥500 | 4 | 2,964 | 2.773 (2.112, 3.641) | 0.023 | 90.3 | <0.001 | |
| By type | |||||||
| Resected | 8 | 5,059 | 2.334 (1.532, 3.555) | <0.001 | 74.2 | <0.001 | |
| Mixed | 3 | 1,354 | 1.37 (0.465, 4.039) | 0.568 | 95.2 | <0.001 | |
| Overall (CPFE vs. normal) | 5 | 2,717 | 3.629 (2.975, 4.429) | <0.001 | 0 | 0.669 | |
| By analysis method | |||||||
| Univariate | 1 | 1,143 | 3.55 (2.795, 4.509) | <0.001 | NA | NA | |
| Multivariate | 4 | 1,574 | 3.816 (2.664, 5.465) | <0.001 | 0 | 0.521 | |
| By sample size | |||||||
| <500 | 3 | 889 | 4.881 (2.933, 8.124) | <0.001 | 0 | 0.79 | |
| ≥500 | 2 | 1,828 | 3.441 (2.772, 4.271) | <0.001 | 0 | 0.548 | |
| By type | |||||||
| Resected | 4 | 1,574 | 3.816 (2.664, 5.465) | <0.001 | 0 | 0.521 | |
| Mixed | 1 | 1,143 | 3.55 (2.795, 4.509) | <0.001 | NA | NA | |
| Overall (fibrosis vs. normal) | 5 | 2,717 | 2.61 (1.725, 3.947) | <0.001 | 0 | 0.53 | |
| By analysis method | |||||||
| Univariate | 1 | 1,143 | 3.57 (1.787, 7.13) | <0.001 | NA | NA | |
| Multivariate | 4 | 1,574 | 2.192 (1.308, 3.673) | 0.003 | 0 | 0.584 | |
| By sample size | |||||||
| <500 | 3 | 889 | 2.66 (1.356, 5.218) | 0.004 | 9.4 | 0.556 | |
| ≥500 | 2 | 1,828 | 2.58 (1.527, 4.358) | <0.001 | 49.8 | 0.158 | |
| By type | |||||||
| Resected | 4 | 1,574 | 2.192 (1.308, 3.673) | 0.003 | 0 | 0.584 | |
| Mixed | 1 | 1,143 | 3.57 (1.787, 7.13) | <0.001 | NA | NA | |
| Overall (emphysema vs. normal) | 5 | 2,717 | 1.524 (1.316, 1.765) | <0.001 | 0 | 0.675 | |
| By analysis method | |||||||
| Univariate | 1 | 1,143 | 1.62 (1.368, 1.918) | <0.001 | NA | NA | |
| Multivariate | 4 | 1,574 | 1.263 (0.939, 1.699) | 0.122 | 0 | 0.962 | |
| By sample size | |||||||
| <500 | 3 | 889 | 1.246 (0.81, 1.917) | 0.361 | 0 | 0.869 | |
| ≥500 | 2 | 1,828 | 1.565 (1.339, 1.829) | <0.001 | 9 | 0.295 | |
| By treatment | |||||||
| Resected | 4 | 1,574 | 1.263 (0.939, 1.699) | 0.122 | 0 | 0.962 | |
| Mixed | 1 | 1,143 | 1.62 (1.368, 1.918) | <0.001 | NA | NA | |
a, numbers of studies included in the meta-analysis; b, number of patients of included studies. HR, hazard ratio; 95% CI, confidence interval; P, P value of pooled HR; I2, value of Higgins I-squared statistics; Ph, P value of Heterogeneity test; CPFE, combined pulmonary fibrosis and emphysema; NA, not available.