Table 1.
Sociodemographics at index date
| Knee replacement | ||
|---|---|---|
| Case (n = 218) | Control (n = 540) | |
| Time to KR after cohort entry, % (n) | ||
| Between year 1 and year 2 | 10.6% (23) | – |
| Between year 2 and year 3 | 15.1% (33) | – |
| Between year 3 and year 4 | 18.8% (41) | – |
| Between year 4 and year 5 | 17.9% (39) | – |
| Between year 5 and year 6 | 12.8% (28) | – |
| Between year 6 and year 7 | 7.8% (17) | – |
| Between year 7 and year 8 | 8.3% (18) | – |
| Between year 8 and year 9 | 8.7% (19) | – |
| Median (IQR) (years) | 4.3 (1.0–8.9) | |
| OAI subcohort, % (n) | ||
| Progression | 61.9% (135) | 58.5% (316) |
| Incidence | 38.1% (83) | 41.5% (224) |
| Age (years), median (IQR) | 68.9 (61.8–74.3) | 68.6 (61.6–73.8) |
| Female, % (n) | 60.6% (132) | 61.1% (330) |
| Race, % (n) | (n = 217) | |
| White or Caucasian | 83.9% (182) | 78.0% (421) |
| Black or African American | 12.5% (27) | 19.4% (105) |
| Asian | 1.8% (4) | 0.4% (2) |
| Other non-white | 1.8% (4) | 2.2% (12) |
| Income level USD, % (n) | ||
| Less than $25,000 | 10.6% (23) | 12.4% (67) |
| $25,000 to < $50,000 | 28.0% (61) | 30.6% (165) |
| $50,000 to < $100,000 | 38.0% (83) | 38.9% (210) |
| $100,000 or greater | 23.4% (51) | 18.1% (98) |
| Education level, % (n) | ||
| Less than high school graduate | 0.9% (2) | 4.1% (22) |
| High school graduate | 19.3% (42) | 10.9% (59) |
| Some college | 26.6% (58) | 30.7% (166) |
| College graduate | 18.3% (40) | 18.2% (98) |
| Some graduate school | 6.9% (15) | 7.2% (39) |
| Graduate degree | 28.0% (61) | 28.9% (156) |
Data shown are proportion of patients (%), number of patients (n), age in years, or median (interquartile range (IQR))
KR knee replacement, OAI Osteoarthritis Initiative