Description of the study population. Data are n (%) unless otherwise indicated.
| Characteristics | Values |
|---|---|
| Total | 6690 |
| Female | 4803 (72) |
| Male | 1887 (28) |
| Diagnosis | |
| Rheumatoid arthritis | 5234 (78) |
| Other inflammatory arthritis | 1456 (22) |
| Other unspecified, noninfectious arthritis | 890 (14) |
| Psoriatic arthritis | 343 (5) |
| Ankylosing spondylitis | 223 (3) |
| Mean age at index surgery, yrs (range) | 63 (12–92) |
| Mean followup, yrs (SD) | 9.5 (5.6) |
| Year of surgery | |
| 1992–1998 | 3445 (52) |
| 1999–2005 | 1953 (29) |
| 2006–2012 | 1292 (19) |
| Charlson Comorbidity Index | |
| Low | 1650 (25) |
| Moderate | 4804 (72) |
| High | 236 (3) |
| Implant fixation | |
| Cemented | 5590 (83) |
| Uncemented | 476 (7) |
| Othera | 587 (9) |
| Missing | 37 (1) |
| Surgical approach | |
| Posterior | 3931 (59) |
| Not posterior | 2675 (40) |
| Missing | 84 (1) |
| Revision after index surgery | |
| No | 6058 (91) |
| Yes | 632 (9) |
| Re-admission within 90 days after index surgery | |
| No | 4669 (70) |
| Yes | 2021 (30) |
| Level of education | |
| 9 years | 3125 (47) |
| High school | 2351 (35) |
| University | 1056 (16) |
| None | 158 (2) |
| Income | |
| 1st quarter | 1719 (26) |
| 2nd quarter | 1700 (25) |
| 3rd quarter | 1646 (25) |
| 4th quarter | 1612 (24) |
| Unknown | 13 (0) |
↵a Hybrid, reversed hybrid, and resurfacing.