Characteristics of 813 patients with incident rheumatoid arthritis (RA) in Olmsted County, Minnesota, USA, 1980–2007, by time period of RA incidence.
| Variable | 1980–1994, n = 349 | 1995–2007, n = 464 | p |
|---|---|---|---|
| Age, yrs, mean ± SD | 56.3 ± 15.9 | 55.6 ± 15.5 | 0.44 |
| Women, n (%) | 236 (68) | 320 (69) | 0.68 |
| Length of followup, yrs, mean ± SD | 14.6 ± 7.2 | 5.9 ± 3.5 | |
| Smokers, n (%) | < 0.001 | ||
| Current | 98 (28) | 80 (17) | |
| Former | 116 (33) | 155 (33) | |
| Rheumatoid factor-positive, n (%) | 231 (66) | 306 (66) | 0.94 |
| Obesity (BMI ≥ 30 kg/m2) | 111 (32) | 210 (45) | < 0.001 |
| Medication use by 5 yrs after RA incidence date, n (%)* | |||
| Methotrexate | 98 (30) | 284 (64) | < 0.001 |
| Hydroxychloroquine | 141 (42) | 290 (64) | < 0.001 |
| Other DMARD | 125 (37) | 92 (23) | < 0.001 |
| Biologic response modifiers | 0 (0) | 80 (20) | < 0.001 |
| Corticosteroids | 173 (51) | 361 (81) | < 0.001 |
↵* Percentages estimated using Kaplan-Meier methods. Comparison performed using log-rank test. BMI: body mass index; DMARD: disease-modifying antirheumatic drugs.