Patient characteristics of the bariatric surgery (BS) and total knee/hip arthroplasty (TKA/THA) cohort
| BS first (N=1894) | TKA/THA first (N=1000) | P value | |
| Age at first surgery (IQR) | 58 (52–64) | 58 (52–62) | 0.008 |
| Female, n (%) | 1452 (76.7) | 775 (77.5) | 0.611 |
| Race, n (%) | 0.271 | ||
| Black | 229 (12.1) | 141 (14.1) | |
| White | 1456 (76.9) | 757 (75.7) | |
| Other | 209 (11.0) | 102 (10.2) | |
| Insurance, n (%) | <0.001 | ||
| Commercial | 1000 (52.8) | 574 (57.4) | |
| Medicaid | 115 (6.1) | 65 (6.5) | |
| Medicare | 665 (35.1) | 286 (28.6) | |
| Uninsured | 2 (0.1) | 9 (0.9) | |
| Unknown | 112 (5.9) | 66 (6.6) | |
| Charlson-Deyo Index at first surgery, n (%) | <0.001 | ||
| 0 | 1140 (60.2) | 598 (59.8) | |
| 1 | 446 (23.5) | 295 (29.5) | |
| 2 | 199 (10.5) | 64 (6.4) | |
| 3+ | 109 (5.8) | 43 (4.3) | |
| Charlson-Deyo Index at second surgery, n (%) | |||
| 0 | 1262 (66.6) | 584 (58.4) | <0.001 |
| 1 | 466 (24.6) | 245 (24.5) | |
| 2 | 100 (5.3) | 101 (10.1) | |
| 3+ | 66 (3.5) | 70 (7.0) | |
| Obesity at second surgery, n (%) | 1050 (55.4) | 922 (92.2) | <0.001 |
| Region, n (%) | 0.018 | ||
| Midwest | 453 (23.9) | 273 (27.3) | |
| Northeast | 367 (19.4) | 183 (18.3) | |
| South | 782 (41.3) | 427 (42.7) | |
| West | 292 (15.4) | 117 (11.7) | |
| Time Between two surgeries, n (%) | <0.001 | ||
| <6 months | 125 (6.6) | 35 (3.5) | |
| 6 months–1 year | 299 (15.8) | 58 (5.8) | |
| 1–2 years | 419 (22.1) | 203 (20.3) | |
| 2–3 years | 354 (18.7) | 242 (24.2) | |
| 3–4 years | 338 (17.8) | 233 (23.3) | |
| 4–5 years | 359 (19.0) | 229 (22.9) | |