Patient and hospital characteristics by hospital procedure volume for cancer surgery in Ontario
| Characteristic | Hospital volume | p value | |||
|---|---|---|---|---|---|
| Low | Low–medium | Medium–high | High | ||
| Breast (n = 14 346) | |||||
| Procedure volume cut-off points/3 yr* | ≤ 102 | 103–158 | 159–264 | ≥ 265 | NA |
| No. of cases (and %) | 3569 (24.9) | 3540 (24.7) | 3603 (25.1) | 3634 (25.3) | NA |
| No. of hospitals | 94 | 29 | 19 | 10 | NA |
| No. of cases in teaching hospitals (and %) | 159 (4.5) | 642 (18.1) | 982 (27.3) | 2889 (79.5) | < 0.001 |
| Median age of patients, yr | 63 | 62 | 60 | 60 | < 0.001 |
| Stage T3 or T4, %† | 8.1 | 10.0 | 10.4 | 9.9 | 0.85 |
| Node positive, %† | 27.6 | 26.8 | 31.9 | 31.4 | 0.51 |
| Operative death, %† | 0.3 | 0.2 | 0.3 | 0.1 | 0.12 |
| Colon (n = 8398) | |||||
| Procedure volume cut-off points/3 yr* | ≤ 61 | 62–90 | 91–137 | ≥ 138 | NA |
| No. of cases (and %) | 2092 (24.9) | 2139 (25.5) | 2076 (24.7) | 2091 (24.9) | NA |
| No of hospitals | 90 | 28 | 19 | 14 | NA |
| No. of cases in teaching hospitals (and %) | 0(0) | 563 (26.3) | 572 (27.6) | 1325 (63.4) | < 0.001 |
| Median age of patients, yr | 70 | 70 | 70 | 70 | 0.59 |
| Stage T3 or T4, %† | 83.8 | 83.3 | 83.5 | 83.1 | 1.00 |
| Node positive, %† | 42.6 | 39.2 | 38.6 | 35.7 | 0.50 |
| Operative death, % | 4.2 | 4.9 | 4.3 | 4.5 | 0.72 |
| Lung (n = 2698) | |||||
| Procedure volume cut-off points/3 yr* | ≤ 32 | 33–85 | 86–130 | ≥ 131 | NA |
| No. of cases (and %) | 653 (24.2) | 730 (27.1) | 644 (23.9) | 671 (24.9) | NA |
| No. of hospitals | 42 | 14 | 7 | 4 | NA |
| No. of cases in teaching hospitals (and %) | 43 (6.6) | 426 (58.4) | 332 (51.6) | 671 (100.0) | < 0.001 |
| Median age of patients, yr | 64 | 65 | 65 | 66 | 0.23 |
| Stage T3 or T44, %† | 14.5 | 11.9 | 12.3 | 9.9 | 0.66 |
| Node positive, %† | 35.4 | 38.7 | 36.3 | 38.9 | 0.88 |
| Operative death, % | 5.8 | 5.9 | 3.7 | 2.4 | <0.001 |
| Esophagus (n = 629) | |||||
| Procedure volume cut-off points/6 yr‡ | ≤ 7 | 8–19 | 20–43 | ≥ 44 | NA |
| No. of cases (and %) | 147 (23.4) | 174 (27.7) | 155 (24.6) | 153 (24.3) | NA |
| No. of hospitals | 46 | 15 | 3 | 4 | NA |
| No. of cases in teaching hospitals (and %) | 27 (18.4) | 80 (46.0) | 132 (85.2) | 153 (100.0) | < 0.001 |
| Median age of patients, yr | 63 | 65 | 65 | 65 | 0.31 |
| Stage T3 or T4, %† | 65.2 | 80.5 | 67.1 | 71.0 | 0.17 |
| Node positive, %† | 61.4 | 60.0 | 60.0 | 62.0 | 0.99 |
| Operative death (%) | 12.9 | 11.5 | 5.8 | 11.8 | 0.17 |
| Liver (n = 362) | |||||
| Procedure volume cut-off points/6 yr§ | ≤ 23 | ≥ 24 | NA | ||
| No. of cases (and %) | 178 (49.2) | 184 (50.8) | NA | ||
| No. of hospitals | 38 | 3 | NA | ||
| No. of cases in teaching hospitals (and %) | 116 (65.2) | 184 (100.0) | < 0.001 | ||
| Median age of patients, yr | 62 | 63 | 0.35 | ||
| > 1 lesion, %† | 21.8 | 25.6 | 0.41 | ||
| Lesion size > 5 cm† | 42.9 | 45.0 | 0.70 | ||
| Operative death, % | 6.7 | 0.5 | <0.01 | ||
↵* Date of diagnosis, Jan. 1, 1991 to Dec. 31, 1993
↵† Measures based on random samples of pathology reports (979 breast, 960 colon, 692 lung, 301 esophagus and 354 liver resections).
↵‡ Date of diagnosis Jan. 1, 1990, to Dec. 31, 1995.
↵§ Date of hospital admission for major liver resection related to a cancer diagnosis, Jan. 1, 1990, to Dec. 31, 1995.