Table 2 Results from survival and Cox regression analyses on hospital volume for 14,496 cemented medial Oxford III unicompartmental knee arthroplasty in NARA 2000-2012
Annual hospital volume groups | Number of procedures | Number of revisions (%) | Number of deathsa (%) | K-M 2-year survival (95%CI) | K-M 10-year survival (95%CI) | Cox Regression Unadjusted HR(95%CI) 10 years | p-value | Cox Regression Adjusted RR(95%CI) 10 years | p-value |
|---|---|---|---|---|---|---|---|---|---|
≤11 | 3528 | 481 (13.6) | 231 (6.5) | 93 (92.4-94.0) | 80 (78.0-82.0) | 1.0 (ref) | 1.0 (ref) | ||
12-23 | 3759 | 429 (11.4) | 237 (6.3) | 95 (94.1-95.7) | 83 (80.8-84.4) | 0.85 (0.75-0.97) | 0.017 | 0.87 (0.76-0.99) | 0.036 |
24-43 | 3533 | 293 (8.3) | 185 (5.2) | 95 (94.1-95.7) | 83 (80.2-86.2) | 0.78 (0.67-0.90) | 0.001 | 0.78 (0.68-0.91) | 0.002 |
≥44 | 3676 | 351 (9.5) | 227 (6.2) | 95 (94.3-95.9) | 83 (80.7-85.5) | 0.82 (0.72-0.95) | 0.006 | 0.82 (0.70-0.94) | 0.006 |