Table 1. Patient, surgeon, and hospital characteristics and outcomes by age group.
| Factors | Age <65 (N=8176) (32%) | Age 65–74 (N=6252) (24%) | Age ⩾75 (N=11 109) (44%) | P-value |
|---|---|---|---|---|
|
Patient factors | ||||
| Sex | ||||
| Male | 4192 (51.3) | 3059 (48.9) | 4454 (40.1) | <0.0001 |
| Female | 3984 (48.7) | 3193 (51.1) | 6655 (59.9) | |
| Race | ||||
| White | 5177 (63.3) | 4523 (72.3) | 9111 (82.0) | <0.0001 |
| Black | 1427 (17.5) | 843 (13.5) | 876 (7.9) | |
| Other | 1291 (15.8) | 708 (11.3) | 806 (7.3) | |
| Unknown | 281 (3.4) | 178 (2.9) | 316 (2.8) | |
| Medicaid Insurance | 2723 (33.3) | 1711 (27.4) | 3211 (28.9) | <0.0001 |
| Comorbidities | ||||
| Hypertension | 3428 (41.9) | 3968 (63.5) | 7834 (70.5) | <0.0001 |
| Congestive heart failure | 213 (2.6) | 501 (8.0) | 1696 (15.3) | <0.0001 |
| Diabetes mellitus | 1381 (16.9) | 1676 (26.8) | 2498 (22.5) | <0.0001 |
| Chronic obstructive pulmonary disease | 886 (10.8) | 1217 (19.5) | 2230 (20.1) | <0.0001 |
| Peripheral vascular disease | 136 (1.7) | 299 (4.8) | 807 (7.3) | <0.0001 |
| Renal failure | 175 (2.1) | 326 (5.2) | 938 (8.4) | <0.0001 |
| Liver disease | 303 (3.7) | 198 (3.2) | 308 (2.8) | 0.001 |
| Anaemia | 184 (2.2) | 279 (4.5) | 851 (7.7) | <0.0001 |
| Obesity | 724 (8.9) | 500 (8.0) | 448 (4.0) | <0.0001 |
| Unscheduled admission | 2332 (28.5) | 1770 (28.3) | 4360 (39.2) | <0.0001 |
|
Oncologic factors | ||||
| T classification | ||||
| 1 | 1559 (19.1) | 1105 (17.7) | 1446 (13.0) | <0.0001 |
| 2 | 1217 (14.9) | 1106 (17.7) | 1949 (17.5) | |
| 3 | 4511 (55.2) | 3463 (55.4) | 6629 (59.7) | |
| 4 | 889 (10.9) | 578 (9.2) | 1085 (9.8) | |
| N classification | ||||
| 0 | 5008 (61.3) | 4138 (66.2) | 7714 (69.4) | <0.0001 |
| 1 | 2087 (25.5) | 1432 (22.9) | 2305 (20.8) | |
| 2 | 1081 (13.2) | 682 (10.9) | 1090 (9.8) | |
| AJCC stage | ||||
| I | 2331 (28.5) | 1903 (30.4) | 3022 (27.2) | <0.0001 |
| II | 2678 (32.8) | 2236 (35.8) | 4692 (42.2) | |
| III | 3167 (38.7) | 2113 (33.8) | 3395 (30.6) | |
| Adjuvant chemotherapy receipt for stage III | 2313 (73.0) | 1318 (62.4) | 1126 (33.2) | <0.0001 |
|
Operative factors | ||||
| Type of colectomy | ||||
| Right | 3562 (43.6) | 2192 (35.1) | 2975 (26.8) | <0.0001 |
| Left | 4071 (49.8) | 3786 (60.6) | 7653 (68.9) | |
| Partial | 331 (4.0) | 206 (3.3) | 385 (3.5) | |
| Total | 212 (2.6) | 68 (1.1) | 96 (0.9) | |
| Operative approach | ||||
| Open | 5765 (70.5) | 4570 (73.1) | 8472 (76.3) | <0.0001 |
| Minimally invasive | 2411 (29.5) | 1682 (26.9) | 2637 (23.7) | |
| Year of surgery | ||||
| 2004–2005 | 2078 (25.4) | 1705 (27.3) | 2981 (26.8) | 0.02 |
| 2006–2007 | 2082 (25.5) | 1657 (26.5) | 2892 (26.0) | |
| 2008–2009 | 2071 (25.3) | 1481 (23.7) | 2752 (24.8) | |
| 2010–2011 | 1945 (23.8) | 1409 (22.5) | 2484 (22.4) | |
|
Surgeon factors | ||||
| Board-certification | ||||
| Surgery | 6335 (77.5) | 4900 (78.4) | 8878 (79.9) | 0.0002 |
| Colorectal surgery | 1841 (22.5) | 1352 (21.6) | 2231 (20.1) | |
| Years in practice | ||||
| <5 | 921 (11.3) | 598 (9.6) | 1060 (9.5) | <0.0001 |
| 5–9 | 1371 (16.8) | 1071 (17.1) | 1705 (15.4) | |
| 10–19 | 2751 (33.7) | 2116 (33.8) | 3599 (32.4) | |
| ⩾20 | 3133 (38.2) | 2467 (39.5) | 4745 (42.7) | |
| Annual colon cancer resection volume | ||||
| Low (1–5) | 2488 (30.4) | 1793 (28.7) | 3235 (29.1) | 0.007 |
| Medium (5–10) | 2183 (26.7) | 1744 (27.9) | 3203 (28.8) | |
| High (>10) | 3505 (42.9) | 2715 (43.4) | 4671 (42.1) | |
|
Hospital Factors | ||||
| Major academic center | 3861 (47.2) | 2811 (45.0) | 4415 (39.7) | <0.0001 |
| Location | ||||
| Urban | 7716 (94.4) | 5812 (93.0) | 10 255 (92.3) | <0.0001 |
| Rural | 460 (5.6) | 440 (7.0) | 854 (7.7) | |
| Annual colon cancer resection volume | ||||
| Low (1–30) | 2549 (31.2) | 1910 (30.6) | 3483 (31.3) | 0.63 |
| Medium (31–55) | 2407 (29.4) | 1879 (30.0) | 3339 (30.1) | |
| High (>55) | 3220 (39.4) | 2463 (39.4) | 4287 (38.6) | |
|
Outcomes | ||||
| Major complication | ||||
| Surgical site infection | 610 (7.5) | 503 (8.0) | 855 (7.7) | 0.43 |
| Abdominal abscess | 215 (2.6) | 147 (2.3) | 277 (2.5) | 0.57 |
| Anastomotic leak/GI complication | 816 (10.0) | 736 (11.8) | 1422 (12.8) | <0.0001 |
| Sepsis | 225 (2.7) | 263 (4.2) | 626 (5.6) | <0.0001 |
| Pneumonia | 18 (0.2) | 48 (0.8) | 78 (0.7) | <0.0001 |
| Pulmonary failure | 210 (2.6) | 350 (5.6) | 928 (8.3) | <0.0001 |
| Myocardial infarction | 40 (0.5) | 87 (1.4) | 274 (2.5) | <0.0001 |
| Venous thromboembolism | 119 (1.5) | 147 (2.3) | 323 (2.9) | <0.0001 |
| Acute renal failure | 196 (2.4) | 363 (5.8) | 885 (8.0) | <0.0001 |
| Gastrointestinal bleeding | 149 (1.8) | 177 (2.8) | 642 (5.8) | <0.0001 |
| Haemorrhage | 83 (1.0) | 87 (1.4) | 194 (1.7) | 0.0001 |
| Any major complication | 1852 (22.6) | 1798 (28.8) | 3945 (35.5) | <0.0001 |
| 1-Year overall mortality | 226 (2.8) | 401 (6.4) | 1544 (13.9) | <0.0001 |
Abbreviation: GI=gastrointestinal.