Table 4. Results of included studies regarding mortality.
| Authors | Surgeon volumes | Mortality (%) per surgeon volume | AOR/HR (95% CI) | P value |
|---|---|---|---|---|
| Badhwar et al. (20) | Operative mortality: | Operative mortality: | High volume as reference: | |
| <5.3 MVO | 1.42% | AOR: 2.27 (1.69–3.04) | <0.0001 | |
| >20.9 MVO | 0.70% | |||
| 30-day mortality: | 30-day mortality: | High volume as reference: | ||
| <5.3 MVO | 1.53% | AOR: 2.25 (1.68–3.01) | <0.001 | |
| >20.9 MVO | 0.99% | |||
| 1-year mortality: | 1-year mortality: | High volume as reference: | ||
| <5.3 MVO | 9.37% | AHR: 1.60 (1.32–1.93) | Unknown | |
| >20.9 MVO | 6.11% | |||
| Chikwe et al. (21) | 1-year mortality: | 1-year mortality: | AHR: | |
| <10 MVO | 5.9% | <10: reference | ||
| 11–24 MVO | 4.2% | 11–24 MVO: 0.72 (0.42–1.22)a | ||
| 25–50 MVO | 3% | 25–50 MVO: 0.52 (0.31–0.85) | Unknown | |
| >51 MVO | 2.2% | >51 MVO: 0.46 (0.28–0.76) | ||
| Ch’ng et al. (11) | 30-day mortality: | 30-day mortality: | OR per 20 extra operations: | |
| 3 MVO | 0% | 0.84 (0.74–0.95) | 0.003 | |
| 10 MVO | 12% | OR per volume group: | ||
| 20 MVO | 7% | 10 MVO: reference | ||
| 50 MVO | 4% | 20 MVO: 0.55 (0.50–0.60)b | <0.0001c | |
| 110 MVO | 2% | 50 MVO: 0.31 (0.27–0.34)b | <0.0001c | |
| 110 MVO: 0.15 (0.13–0.17)b | <0.0001c | |||
| Hannan et al. (22) | 4-year mortality: | 4-year mortality: | >47 MVO vs. other surgeon volume quartiles: | |
| <17 MVO | 5.5% | AHR: 0.63 (0.36–1.09)a | 0.15 | |
| 18–30 MVO | 5.1% | AOR: >47 MVO vs. <17 MVO: | ||
| 31–46 MVO | 5.9% | 0.65 (0.18–2.39)a,b | 0.519c | |
| >47 MVO | 4.1% | |||
| Kilic et al. (23) | Operative mortality: | Operative mortality: | OR (multivariate analysis): | |
| 1–6.5 MVO | 10.1% | 1–6.5 MVO: 2.22 (1.53–3.23) | <0.001 | |
| 6.6–20.5 MVO | 6.1% | 6.6–20.5 MVO: 1.50 (1.07–2.11) | 0.02 | |
| >20.5 MVO | 4.6% | >20.5 MVO: reference |
a, not significant; b, OR was not given in the article and was calculated by the authors; c, P value was not given in the article and was calculated by the authors. AOR, adjusted odds ratio; HR, hazard ratio; CI, confidence interval; MVO, mitral valve operations; OR, odds ratio.