Table 2.
Patient Characteristics by Surgeon and Hospital Volume
| Patient characteristics | Total n (%) | Surgeon volume |
Hospital volume |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Very low | Low | Medium | High | Very high | Very low | Low | Medium | High | Very high | ||
| Total cohort, n | 1,290 | 1,577 | 1,682 | 843 | 608 | 1,497 | 1,677 | 1,437 | 815 | 756 | |
| Age, y, % | |||||||||||
| 66–69 | 1,142 (18.3) | 19.2 | 17.9 | 16.4 | 19.6 | 18.8 | 17.8 | 18.0 | 18.8 | 19.8 | 17.1 |
| 70–74 | 1,643 (26.3) | 26.6 | 26.6 | 25.9 | 25.7 | 25.7 | 24.8 | 26.1 | 26.9 | 25.6 | 28.2 |
| 75–79 | 1,522 (24.3) | 21.9 | 25.1 | 25.5 | 24.3 | 25.7 | 22.7 | 25.4 | 24.2 | 25.2 | 25.0 |
| ≥ 80 | 1,951 (31.2) | 32.3 | 30.4 | 32.2 | 30.4 | 29.9 | 34.8 | 30.5 | 30.1 | 29.5 | 29.8 |
| Gender, % | |||||||||||
| Male | 3,270 (52.3) | 50.7* | 53.1 | 53.4 | 52.1 | 50.3 | 51.5 | 54.0 | 51.6 | 51.8 | 50.5 |
| Female | 2,988 (47.8) | 49.3 | 46.9 | 46.6 | 47.9 | 49.7 | 48.5 | 46.0 | 48.4 | 48.2 | 49.5 |
| Marital status (%) | |||||||||||
| Divorced/separated/single | 734 (11.9) | 14.7* | 13.0 | 9.5 | 11.0 | 10.1 | 13.0 | 10.9 | 11.3 | 14.2 | 10.8 |
| Married | 3,503 (56.9) | 54.7 | 56.6 | 58.0 | 57.9 | 58.6 | 54.7 | 57.5 | 58.2 | 55.9 | 58.2 |
| Widowed | 1,919 (31.2) | 30.7 | 30.4 | 32.5 | 31.1 | 31.4 | 32.2 | 31.6 | 30.6 | 30.0 | 31.0 |
| Race/ethnicity, % | |||||||||||
| Caucasian | 5,399 (86.3) | 79.0† | 85.7 | 90.4 | 87.0 | 94.4 | 81.0† | 85.1 | 93.7 | 79.8 | 92.4 |
| African-American | 261 (4.2) | 5.9 | 4.9 | 1.7 | 4.3 | 3.0 | 6.0 | 3.1 | 2.3 | 8.5 | 1.9 |
| Other/unknown | 53 (0.9) | 0.6 | 1.5 | 0.8 | 0.6 | 0.3 | 1.1 | 1.0 | 0.6 | 1.1 | 0.4 |
| Asian/Pacific Islander | 281 (4.5) | 6.7 | 4.2 | 3.9 | 5.7 | 0.8 | 4.4 | 6.6 | 1.4 | 8.3 | 2.1 |
| Hispanic | 260 (4.2) | 7.8 | 3.7 | 3.3 | 2.5 | 1.5 | 7.4 | 4.3 | 2.1 | 2.3 | 3.2 |
| Cancer stage, % | |||||||||||
| I | 2,790 (44.6) | 41.4 | 43.5 | 46.7 | 45.1 | 47.4 | 45.2 | 45.0 | 45.0 | 42.8 | 44.1 |
| II | 1,820 (29.1) | 31.3 | 29.1 | 27.9 | 26.6 | 28.5 | 28.6 | 29.1 | 29.9 | 29.0 | 28.3 |
| III | 1,648 (26.3) | 27.3 | 27.4 | 25.4 | 28.4 | 24.2 | 26.3 | 25.9 | 25.1 | 28.2 | 27.7 |
| T stage, % | |||||||||||
| T0 | 57 (0.9) | 0.8 | 0.6 | 1.0 | 0.8 | 1.3 | 1.1 | 1.0 | 0.7 | 1.0 | 0.5 |
| T1 | 1,496 (23.9) | 22.2 | 24.2 | 23.1 | 25.9 | 24.2 | 24.2 | 24.5 | 23.7 | 22.5 | 24.6 |
| T2 | 1,566 (25.0) | 24.3 | 24.0 | 27.5 | 23.7 | 26.6 | 24.7 | 25.2 | 26.0 | 23.8 | 25.0 |
| T3 | 2,877 (46.0) | 48.1 | 46.5 | 44.7 | 44.8 | 45.7 | 45.5 | 44.9 | 45.2 | 49.1 | 47.0 |
| T4 | 262 (4.2) | 4.6 | 4.6 | 3.9 | 4.7 | 2.1 | 4.6 | 4.5 | 4.5 | 3.7 | 2.9 |
| Comorbidity score, % | |||||||||||
| 0 | 3,200 (51.1) | 51.0 | 48.5 | 52.6 | 51.8 | 50.8 | 51.2 | 52.4 | 49.7 | 51.4 | 51.6 |
| 1 | 1,365 (21.8) | 21.2 | 21.1 | 22.5 | 22.5 | 22.9 | 22.9 | 20.4 | 21.3 | 22.1 | 23.0 |
| 2+ | 1,693 (27.1) | 27.8 | 30.4 | 25.0 | 25.6 | 26.3 | 25.9 | 27.3 | 29.0 | 26.5 | 25.4 |
| Emergent admission, % | |||||||||||
| No | 5,725 (91.4) | 88.9† | 92.3 | 91.4 | 92.5 | 94.2 | 90.1 | 92.3 | 91.2 | 90.8 | 93.0 |
| Yes | 533 (8.6) | 11.1 | 7.7 | 8.6 | 7.5 | 5.8 | 9.9 | 7.7 | 8.8 | 9.2 | 7.0 |
| Perforation, % | |||||||||||
| No | 6,214 (99.3) | 99.5 | 99.1 | 99.2 | 99.8 | 99.5 | 99.1 | 99.4 | 99.2 | 99.3 | 99.7 |
| Yes | 43 (0.7) | 0.5 | 0.9 | 0.8 | 0.2 | 0.5 | 0.9 | 0.6 | 0.8 | 0.7 | 0.3 |
| Obstruction, % | |||||||||||
| No | 5,922 (94.6) | 93.5 | 94.5 | 94.9 | 95.3 | 95.9 | 94.1 | 94.7 | 95.1 | 96.1 | 93.3 |
| Yes | 36 (5.4) | 6.5 | 5.5 | 5.1 | 4.7 | 4.1 | 6.0 | 5.3 | 4.9 | 3.9 | 6.7 |
| Median household income, $, % | |||||||||||
| < 25,000 | 210 (3.5) | 4.9† | 3.5 | 2.0 | 3.1 | 3.1 | 4.6† | 2.3 | 1.9 | 7.4 | 2.6 |
| 25,001–35,000 | 1,007 (16.6) | 18.7 | 18.3 | 17.2 | 14.7 | 10.0 | 24.9 | 16.2 | 11.8 | 14.8 | 12.5 |
| 35,001–45,000 | 1,660 (27.4) | 24.4 | 26.6 | 31.0 | 31.2 | 22.2 | 31.4 | 29.6 | 24.3 | 26.5 | 21.6 |
| ≥ 45,000+ | 3,179 (52.5) | 52.1 | 51.6 | 50.0 | 50.9 | 64.8 | 39.2 | 51.9 | 61.9 | 51.3 | 63.3 |
| Registry, % | |||||||||||
| San Francisco | 479 (7.7) | 9.1† | 8.8 | 6.0 | 8.0 | 4.6 | 6.5† | 8.3 | 11.3 | 9.2 | 0.1 |
| Connecticut | 953 (15.2) | 11.5 | 14.3 | 15.5 | 11.5 | 28.5 | 6.0 | 8.9 | 24.0 | 15.3 | 31.1 |
| Michigan | 958 (15.3) | 10.6 | 12.4 | 14.3 | 24.2 | 22.0 | 7.2 | 12.6 | 15.5 | 24.8 | 26.7 |
| Hawaii | 153 (2.4) | 3.6 | 2.9 | 1.7 | 3.1 | 0 | 2.0 | 3.5 | 0.0 | 7.7 | 0.0 |
| Iowa | 1,127 (18.0) | 11.1 | 16.7 | 23.7 | 24.3 | 14.8 | 26.1 | 14.5 | 17.9 | 18.8 | 9.4 |
| New Mexico | 257 (4.1) | 7.0 | 5.1 | 3.0 | 3.4 | 0 | 7.6 | 3.5 | 0.0 | 2.7 | 7.8 |
| Seattle | 681 (10.9) | 8.1 | 10.8 | 13.0 | 8.2 | 14.3 | 7.8 | 19.3 | 7.0 | 6.0 | 10.5 |
| Utah | 309 (4.9) | 5.0 | 3.9 | 5.4 | 4.2 | 8.1 | 4.7 | 4.5 | 7.3 | 0.0 | 7.5 |
| Atlanta | 258 (4.1) | 5.4 | 5.0 | 2.8 | 2.9 | 4.9 | 5.9 | 3.8 | 4.7 | 4.5 | 0.0 |
| San Jose | 315 (5.0) | 4.4 | 6.2 | 7.4 | 2.9 | 0 | 2.8 | 5.7 | 5.4 | 4.8 | 6.9 |
| Los Angeles | 743 (11.9) | 23.1 | 13.2 | 7.3 | 7.5 | 2.6 | 21.9 | 15.4 | 6.8 | 6.1 | 0.0 |
| Rural Georgia | 1.1 | 0.6 | 0 | 0 | 0.2 | 1.5 | 0 | 0.1 | 0.0 | 0.0 | |
| Year of diagnosis, % | |||||||||||
| 1991 | 17 (0.3) | 0.2‡ | 0.3 | 0.2 | 0.1 | 0.3 | 0.1 | 0.4 | 0.4 | 0.3 | 0.1 |
| 1992 | 865 (13.8) | 16.0 | 11.5 | 13.8 | 10.4 | 13.2 | 14.6 | 12.9 | 14.9 | 12.8 | 13.0 |
| 1993 | 841 (13.4) | 14.0 | 14.2 | 12.5 | 12.5 | 12.3 | 14.5 | 12.9 | 13.4 | 12.6 | 12.4 |
| 1994 | 789 (12.6) | 13.9 | 13.2 | 13.1 | 10.9 | 9.5 | 14.6 | 12.8 | 10.9 | 11.5 | 12.4 |
| 1995 | 745 (11.9) | 9.7 | 13.8 | 11.3 | 12.8 | 13.0 | 11.2 | 10.8 | 12.5 | 14.0 | 12.8 |
| 1996 | 761 (12.2) | 10.7 | 11.7 | 13.5 | 12.3 | 14.6 | 12.1 | 12.1 | 12.0 | 12.0 | 13.4 |
| 1997 | 748 (11.9) | 10.4 | 12.6 | 13.0 | 12.9 | 10.7 | 10.4 | 13.0 | 11.6 | 13.9 | 11.5 |
| 1998 | 766 (12.2) | 12.0 | 11.8 | 13.0 | 12.7 | 13.7 | 12.2 | 13.0 | 11.8 | 11.2 | 12.7 |
| 1999 | 726 (11.6) | 13.2 | 11.0 | 9.6 | 15.4 | 12.7 | 10.3 | 12.1 | 12.6 | 11.8 | 11.6 |
*
Overall chi-square p value ≤ 0.01.
†
Overall chi-square p value ≤ 0.001.
‡
Overall chi-square p value ≤ 0.0001.