Rate of surgical site infection by intervention type*
| Variable | Intervention type; no (%)† | ||||
|---|---|---|---|---|---|
| Clean | Clean–contaminated | Contaminated | Dirty | Total | |
| No SSI | 6072 (31.68) | 7677 (40.05) | 2745 (14.32) | 1149 (5.99) | 17 643 (92.05) |
| SSI | 129 (0.67) | 413 (3.01) | 407 (2.3) | 318 (1.97) | 1267 (7.95) |
| Total | 6201 (32.35) | 8090 (43.06) | 3152 (16.62) | 1467 (7.97) | 18 910 (100) |
| Infection rate | 2.1 | 5.1 | 12.9 | 21.7 | 6.7 |