Baseline characteristics of patients undergoing hip arthroscopy between 2006 and 2016
| Characteristic | No. (%) of patients*; age | Standardized difference | p value | ||
|---|---|---|---|---|---|
| Overall n = 1906 | 18–39 yr n = 1088 | 40–60 yr n = 818 | |||
| Age, yr, mean ± SD | 36.70 ± 10.92 | 28.84 ± 6.68 | 47.16 ± 5.19 | ||
| Male sex | 841 (44.1) | 512 (47.1) | 329 (40.2) | 0.14 | 0.003 |
| Income quintile† | |||||
| 1 (lowest) | 253 (13.3) | 166 (15.3) | 87 (10.6) | 0.14 | 0.049 |
| 2 | 309 (16.2) | 180 (16.5) | 129 (15.8) | 0.02 | |
| 3 | 367 (19.3) | 201 (18.5) | 166 (20.3) | 0.05 | |
| 4 | 468 (24.6) | 262 (24.1) | 206 (25.2) | 0.03 | |
| 5 (highest) | 504 (26.4) | 275 (25.3) | 229 (28.0) | 0.06 | |
| Charlson Comorbidity Index score† | |||||
| 0 | 1860 (97.6) | 1073 (98.6) | 787 (96.2) | 0.15 | 0.003 |
| 1 | 34 (1.8) | ≤ 15 | ≤ 25 | 0.1 | |
| 2 | ≤ 10 | ≤ 5 | 7 (0.9) | NR | |
| ≥ 3 | ≤ 5 | 0 (0.0) | ≤ 5 | NR | |
| Rheumatoid arthritis† | ≤ 20 | ≤ 5 | 14 (1.7) | NR | 0.006 |
| Osteoarthritis | 123 (6.5) | 39 (3.6) | 84 (10.3) | 0.27 | < 0.001 |
| Diabetes | 66 (3.5) | 25 (2.3) | 41 (5.0) | 0.15 | 0.001 |
| No. of preoperative orthopedic surgeon visits | |||||
| 0 | 478 (25.1) | 281 (25.8) | 197 (24.1) | 0.04 | 0.07 |
| 1 | 575 (30.2) | 342 (31.4) | 233 (28.5) | 0.06 | |
| 2 | 432 (22.7) | 248 (22.8) | 184 (22.5) | 0.01 | |
| ≥ 3 | 421 (22.1) | 217 (19.9) | 204 (24.9) | 0.12 | |
| No. of family physician visits | |||||
| 0 | 119 (6.2) | 65 (6.0) | 54 (6.6) | 0.03 | 0.40 |
| 1 | 183 (9.6) | 115 (10.6) | 68 (8.3) | 0.08 | |
| 2 | 209 (11.0) | 117 (10.8) | 92 (11.2) | 0.02 | |
| ≥ 3 | 1395 (73.2) | 791 (72.7) | 604 (73.8) | 0.03 | |
| Teaching hospital | 1589 (83.4) | 901 (82.8) | 688 (84.1) | 0.03 | 0.45 |
| Institution annual volume | 58.30 ± 31.55 | 58.38 ± 31.19 | 58.21 ± 32.03 | 0.01 | 0.91 |
| Surgeon annual volume | 71.64 ± 64.28 | 70.53 ± 59.01 | 73.11 ± 70.72 | 0.04 | 0.39 |
| Surgeon experience, yr | 14.66 ± 4.75 | 14.86 ± 4.75 | 14.39 ± 4.74 | 0.1 | 0.032 |