Table 1.
Clinical characteristics of rheumatoid arthritis (RA) patients and controls. Values for continuous variables are expressed as medians and interquartile ranges. Values for dichotomous variables are expressed as counts and percentages.
| Characteristic | RA (N = 58) |
Controls (N = 54) |
P |
|---|---|---|---|
| Demographics | |||
| Age, years | 60.9 (9.7) | 62.5 (9.3) | 0.34 |
| White | 53 (91.4%) | 44 (81.5%) | 0.17 |
| Current smoking | 4 (6.9%) | 4 (7.4%) | 1.00 |
| Alcohol | 12 (20.7%) | 10 (18.5%) | 0.82 |
| Post-menopausal | 48 (82.8%) | 44 (81.4%) | 0.80 |
| Inflammatory/Pain Measures | |||
| Tender joint count | 3.0 (1.0, 5.0) | 0.0 (0.0, 0.0) | <0.0001 |
| Swollen joint count | 0.5 (0.0, 3.0) | 0.0 (0.0, 0.0) | <0.0001 |
| C-reactive protein | 1.4 (0.6, 4.1) | 0.6 (0.3, 1.4) | 0.03 |
| Interleukin-6 | 2.8 (1.6, 6.4) | 1.4 (1.2, 2.3) | 0.26 |
| TNF-αa | 1.9 (1.0, 5.0) | 1.3 (1.0, 1.8) | 0.01 |
| DAS28a | 2.7 (2.5, 3.3) | 1.4 (1.3, 1.7) | <0.0001 |
| BPI current pain | 2.0 (1.0, 4.0) | 0.0 (0.0, 0.0) | <0.0001 |
| Sleep/Psych Measures | |||
| HADS Anxietya | 5.5 (4.0, 9.0) | 2.0 (1.0, 4.0) | <0.0001 |
| HADS Depressiona | 3.0 (1.0, 6.0) | 1.0 (0.0, 3.0) | <0.0001 |
| MOS Sleep Index IIa | 30.6 (20.6, 48.9) | 13.3 (5.6, 20.6) | <0.0001 |
| Catastrophizing | 11.0 (4.0, 21.0) | 0.0 (0.0, 3.0) | <0.0001 |
| Medications | |||
| NSAIDs | 22 (37.9%) | 1 (4.4%) | <0.0001 |
| Corticosteroids | 16 (27.6%) | 0 (0.0%) | <0.0001 |
| Non-biologic DMARDs | 38 (65.5%) | 0 (0.0%) | <0.0001 |
| Biologic DMARDs | 27 (46.6%) | 0 (0.0%) | <0.0001 |
a
TNF-α = tumor necrosis factor-alpha. DAS28 = disease activity in 28 joints, measured from tender joint count, swollen joint count and C-reactive protein. HADS = Hospital Anxiety and Depression Scale. MOS = Medical Outcomes Study. NSAIDs = non-steroidal anti-inflammatory drugs. DMARDs = disease modifying anti-rheumatic drugs.