The distribution of the Lifelines population, anticitrullinated protein antibodies (ACPA) positivity, self-reported rheumatoid arthritis (RA) and defined RA among different age groups
| Age (years) | Lifelines population (%) | ACPA positivity (≥6.2 U/mL; %) | Self-reported RA (%) | Defined RA (%) |
|---|---|---|---|---|
| 18–30 | 16.5 | 0.6 | 0.5 | 0.1 |
| 30–40 | 19.7 | 0.8 | 1.0 | 0.1 |
| 40–50 | 34.4 | 0.9 | 2.0 | 0.3 |
| 50–60 | 19.7 | 1.4 | 3.3 | 0.7 |
| 60+ | 9.7 | 1.5 | 5.0 | 0.8 |