Table 2.
Surgeon and statistical model characteristics
| Surgical procedure | BRM | CABG | TKR |
|---|---|---|---|
| Factors included in patient case-mix adjustment | Breast reduction volume | Age, sex, preoperative congestive heart failure, Preoperative cardiogenic shock, diabetes mellitus | Age, sex, coronary artery disease, chronic obstructive pulmonary disease, diabetes mellitus, hypertension, obesity smoking |
| Time period data available | 13 years (18/1/1995–21/12/2007) | 9 years (1/5/2002–30/9/2010) | 14 years (28/7/1999–29/6/2009) |
| Surgeons (N) | 8 | 9 | 13 |
| Surgeon-years (N) | 52 | 48 | 123 |
| Procedures (N) | 1052 | 3254 | 3325 |
| Median number of procedures per surgeon (minimum–maximum) | 61 (11–502) | 290 (52–973) | 99 (10–1871) |
| Mean operative time (SD) | 134.4 (34.5) | 180.9 (62.3) | 101.9 (30.3) |
| Model | GEE (clustering and case-mix adjusted; linear and quadratic model used) | GEE (clustering and case-mix adjusted; logarithmic model used) | GEE (clustering and case-mix adjusted; linear and quadratic model used) |
BRM, bilateral reduction mammoplasty; CABG, coronary artery bypass grafting; GEE, generalised estimating equation; TKR, total knee replacement.