Baseline characteristics of the study population
| Arthralgia patients | Before QC n=183 | After QC n=172 |
|---|---|---|
| Age in years, mean±SD | 48±11 | 49±11 |
| Female sex, n (%) | 143 (79) | 135 (78) |
| Arthralgia duration in months, median (IQR) | 12 (6–24) | 12 (6–24) |
| Tender joint count (53 joints), median (IQR) | 0 (0–3) | 0 (0–3) |
| Rheumatoid factor positive, n (%) | 86 (48) | 79 (46) |
| Follow-up, months (IQR) | 35 (21–52) | 35 (20–58) |
| Arthritis development, n (%) | 105 (58) | 99 (57) |
| Development of RA, n (%) | 48 (26) | 43 (25) |
QC, quality control.