Characteristics of patients and hospitals for people who had one of five major surgical procedures in Ontario, Canada, between 1994 and 1999
| Variable | Oesophaectomy | Colorectal resection | Pancreaticoduodenectomy | Lung resection | Repair of aortic aneurysm |
|---|---|---|---|---|---|
| *Used as a cut-off point to divide patients among high volume hospitals and low volume hospitals for analyses of the outcome of the same procedure. As the distribution of hospital volumes for other procedures usually differed from the distribution of hospital volumes of the procedure whose outcome was being studied, cut-off points used to separate high volume and low volume hospitals varied according to the procedure volume specified as the exposure variable. | |||||
| †Weighted measure of the number of comorbid medical conditions, calculated by using secondary diagnosis codes for hospital admissions for surgical procedure. | |||||
| No of patients | 613 | 18 898 | 686 | 5156 | 6279 |
| No of hospitals | 47 | 134 | 49 | 54 | 57 |
| Average annual hospital volume: | |||||
| Median* (interquartile range) | 8.8 (2.8–16.6) | 52.8 (33.6–87.4) | 5.4 (2.8–11.4) | 45.0 (18.2–86.0) | 42.0 (21.8–92.8) |
| Range | 0.2–19.0 | 0.2–149.8 | 0.2–24.8 | 0.2–129.4 | 0.2–130.0 |
| Mean (SD) age in years | 64.2 (10.7) | 68.8 (11.6) | 62.7 (11.7) | 65.1 (9.6) | 70.7 (7.4) |
| Median (interquartile range) Charlson score† | 4 (2–6) | 0 (0–6) | 1 (0–6) | 1 (0–6) | 0 (0–1) |
| No (%) male | 450 (73.4) | 10 197 (54.0) | 386 (56.3) | 3023 (58.6) | 5168 (82.3) |
| 30 day mortality (No (%)) | 82 (13.4) | 713 (3.8) | 66 (9.6) | 215 (4.2) | 265 (4.2) |