Summary of the performed meta-analyses (random-effects model)
| Meta-analysis | HR/OR (95% CI) | I2 (%) | Degree of heterogeneity |
| Overall analysis (recurrence) | |||
| Recurrence (overall) | OR 4.82 (2.45 to 9.51) | 85 | High |
| Recurrence (local) | OR 2.42 (1.48 to 3.95) | 0 | Low |
| Recurrence (loco-regional) | OR 2.13 (1.32 to 3.45) | 0 | Low |
| Recurrence (pleural) | OR 9.89 (5.95 to 16.44) | 33 | Moderate |
| Recurrence (distant) | OR 3.18 (1.56 to 6.46) | 86 | High |
| Overall analysis (survival) | |||
| Total follow-up (all studies) | HR 2.08 (1.71 to 2.52) | 71 | Moderate |
| Total follow-up (stage I) | HR 4.20 (2.65 to 6.65) | 55 | Moderate |
| Subgroup analysis (overall recurrence) | |||
| Study size (>350 patients) | OR 4.40 (1.52 to 12.73) | 88 | High |
| Positive PLC % (<5%) | OR 10.01 (5.09 to 19.69) | 11 | Low |
| Study score (high quality) | OR 5.07 (1.70 to 15.19) | 82 | High |
| Subgroup analysis (survival) | |||
| Study score (high quality) | HR 1.74 (1.37 to 2.23) | 71 | Moderate |
Please note, the degree of heterogeneity was graded as low (I2 <25%), moderate (I2 =25–75%) or high (I2 >75%).