Characteristics of patients with and without rheumatoid arthritis (RA) who completed the Minnesota Multiphasic Personality Inventory (MMPI).
| Characteristics | Non-RA, n = 135 | RA, n = 148 | p |
|---|---|---|---|
| Age, years, mean (± SD) | 55.4 (± 12.9) | 56.5 (± 12.9) | 0.33 |
| Sex, female | 92 (68%) | 112 (76%) | 0.16 |
| Year of index date, mean (± SD) | 1995.5 (± 9.1) | 1994.5 (± 9.8) | 0.42 |
| Time from MMPI to index date, yrs, mean (± SD) | 14.2 (± 9.0) | 13.7 (± 9.1) | 0.71 |
| MMPI Item 51: Health similar to peers (% true) | 102 (77%) | 106 (74%) | 0.55 |
| Pessimistic explanatory style* | 42 (31%) | 57 (39%) | 0.19 |
| MMPI Depression scale, mean (± SD) | 58.4 (± 10.7) | 58.7 (± 11.2) | 0.83 |
| Rheumatoid factor positivity | — | 96 (65%) | |
| Sedimentation rate, median (25th percentile, 75th percentile) | — | 23.0 (10, 40) | |
| Obesity (body mass index ≥ 30 kg/m2) | 46 (34%) | 56 (38%) | 0.51 |
| Smoking status | 0.13 | ||
| Never | 68 (50%) | 60 (41%) | |
| Current | 20 (15%) | 34 (23%) | |
| Former | 47 (35%) | 54 (36%) | |
| Charlson comorbidity index, mean (± SD) | 0.9 (± 2.2) | 1.3 (± 1.9) | < 0.001 |
| History of depression diagnosis | 76 (58%) | 84 (57%) | 0.88 |
↵* Defined using the MMPI Optimism-Pessimism scale (≥ 60 classified as pessimistic).