Table 1

Baseline characteristics for the treatment courses

VariableRA
(n=1778)
PsA
(n=1391)
P value
Age in years, mean (SD)53.2 (13.8)48.2 (11.9)<0.001
Age, n (%)
 <50 years651 (36.6)755 (54.3)<0.001
 ≥50 years1127 (63.4)636 (45.7)
Female gender, n (%)1341 (75.4)797 (57.3)<0.001
Years on treatment, median (IQR)1.1 (0.4–2.6)1.1 (0.5–2.7)0.65
Disease duration, years, median (IQR)*6.9 (2.3, 14.5)5.2 (1.6, 11.8)<0.001
Current smoking, n (%)252 (14.2)225 (16.2)0.12
DAS28-CRP, mean (SD)†4.0 (1.3)3.5 (1.2)<0.001
MHAQ, median (IQR)‡0.6 (0.3, 1.0)0.6 (0.3, 1.0)0.22
MTX co-medication, n (%)§1265 (73.2)798 (59.1)<0.001
Prednisolone co-medication, n (%)§976 (56.5)400 (29.6)<0.001
Prednisolone dose, n (%)
 >0–5 mg412 (23)135 (10)<0.001
 >5–10 mg264 (15)68 (5)<0.001
 >10 mg269 (16)87 (6)<0.001
Comorbidities
 COPD and/or asthma, n (%)180 (10.1)93 (6.7)0.001
 Diabetes, n (%)127 (7.1)116 (8.3)0.209
  • Continuous variables presented as mean (SD) or median (IQR), dichotomous variables presented as number (%).

  • *Disease duration missing in 266 patients with RA, and 286 patients with PsA.

  • †DAS28-CRP missing in 228 patients with RA and 200 patients with PsA.

  • ‡MHAQ missing in 58 patients with RA and 50 patients with PsA.

  • §MTX and prednisolone co-medication missing in 50 patients with RA and 41 patients with PsA.

  • COPD, chronic obstructive pulmonary disease; CRP, C reactive protein; DAS28, Disease Activity Score for 28 joints; MHAQ, Modified Health Assessment Questionnaire; MTX, methotrexate; PsA, psoriatic arthritis; RA, rheumatoid arthritis; TNFi, tumour necrosis factor inhibitor.