Demographic characteristics
| All patients (N=628) | IA diagnosed ≤30 years (N=137) | IA diagnosed 31–40 years (N=149) | IA diagnosed ≥41 years (N=342) | P value | |
| General information | |||||
| Age at inclusion in the study, mean (SD) | 57.17 (9.98) | 53.01 (9.96)* | 52.76 (7.35)* | 61.06 (9.47) | 0.001 |
| Born in the Netherlands, n (%) | 531 (94.48) | 117 (92.13) | 132 (94.96) | 277 (95.19) | 0.143 |
| Education Bachelor degree or higher, n (%) | 223 (35.51) | 61 (44.53)* | 51 (34.23) | 111 (32.46) | 0.048 |
| Currently in a relationship, n (%) | 423 (67.36) | 89 (64.96) | 100 (67.11) | 234 (68.42) | 0.765 |
| Inflammatory arthritis | |||||
| Diagnosis, n (%) | |||||
| RA | 297 (47.29) | 42 (30.66)*† | 67 (44.97) | 188 (55.32) | 0.001 |
| JIA | 10 (1.59) | 10 (6.45) | 0 | 0 | – |
| SpA (incl. PsA) | 320 (50.96) | 90 (65.69)* | 83 (55.70) | 147 (42.98) | 0.001 |
| Age at diagnosis, mean (SD) | 41.30 (13.08) | 23.76 (6.17)*† | 36.52 (2.48)* | 51.25 (7.77) | 0.001 |
| Disease duration, mean (SD) | 15.89 (11.88) | 29.51 (11.30)*† | 16.30 (8.29)* | 9.68 (7.77) | 0.001 |
| Concerning your IA, have you ever received information about your desire to have children? Yes, n (%) | 139 (22.13) | 45 (33.83)* | 36 (24.66)* | 37 (11.31) | 0.001 |
| Comorbidities | |||||
| Type 2 diabetes mellitus, n (%) | 54 (8.60) | 13 (9.49) | 10 (6.71) | 31 (9.06) | 0.635 |
| Cardiovascular disease,‡ n (%) | 98 (15.61) | 17 (12.41) | 13 (8.72)* | 68 (19.88) | 0.006 |
| Inflammatory bowel disease, n (%) | 21 (3.34) | 5 (3.65) | 7 (5.04) | 7 (2.05) | 0.278 |
| Urogenital comorbidities,§ n (%) | 27 (4.30) | 6 (4.38) | 3 (2.01) | 18 (5.26) | 0.264 |
*P≤0.05 compared with those diagnosed age ≥41 years.
†p≤0.05 compared with those diagnosed age ≥31–40 years.
‡Arterial hypertension, angina pectoris, myocardial infarction, heart failure, stroke, peripheral vascular disease and dyslipidaemia.
§Urogenital infection, sexually transmitted disease, cryptorchidism, varicocele, testicular torsion, epididymitis, prostatitis, inguinal hernia, urogenital surgery, urogenital trauma and exposure to chemicals or radiation that can result in DNA damage.
IA, inflammatory arthritis; JIA, juvenile idiopathic arthritis; PsA, psoriatic arthritis ; RA, rheumatoid arthritis; SpA, spondyloarthritis.