Table 1.
Characteristics of 897 individuals with incident RA 1980–2009 and referents at index date
| Characteristic | RA (N=897) | Non-RA (N=885) | p-value |
|---|---|---|---|
| Age, years, mean (SD) | 56 (16) | 55 (15) | 0.68* |
| Female sex, N (%) | 616 (69) | 606 (68) | 0.93* |
| Decade, N (%) | 0.99* | ||
| 1980s | 198 (22) | 196 (22) | |
| 1990s | 298 (33) | 291 (33) | |
| 2000s | 401 (45) | 398 (45) | |
| White race, N (%) | 832 (93) | 831 (94) | 0.33 |
| Education level | <0.001 | ||
| Less than high school | 90 (10%) | 83 (9 %) | |
| High school | 293 (33%) | 256 (29%) | |
| Technical school/college | 431 (48%) | 396 (45%) | |
| Graduate school | 52 (6%) | 121 (14%) | |
| No documentation | 31 (3%) | 29 (3%) | |
| 27 | |||
| Body mass index, kg/m2, median (IQR) | 27 (24,32) | (24,31) | 0.86 |
| Smoking status, N (%) | 0.001 | ||
| Never | 409 (46) | 481 (54) | |
| Former | 301 (34) | 246 (28) | |
| Current | 187 (21) | 158 (18) | |
| Hypertension | 365 (41%) | 315 (36%) | 0.027 |
| Diabetes mellitus | 96 (11%) | 77 (9%) | 0.15 |
| Dyslipidemia | 507 (57%) | 446 (50%) | 0.01 |
| Myocardial infarction** | 22 (2%) | 26 (3%) | 0.53 |
| Stroke (ischemic or hemorrhagic)** | 10 (1%) | 21 (2%) | 0.042 |
IQR = interquartile range, RA = rheumatoid arthritis, SD = standard deviation
*
matched factor
**
Prior to or on RA incidence/index date