Characteristics, disease activity and disease impact of 439 PSA patients from 13 countries grouped by GDP/capita
| Patients in lowest country GDP/capita tertile (N=114) | Patients in middle country GDP/capita tertile (N=182) | Patients in highest country GDP/capita tertile (N=143) | P value between the tertiles (Effect size)* (95% CI) | |
| Patients characteristics | ||||
| Age (years), mean (SD) | 49.6 (12.3) | 54 (12.4) | 52.2 (12.7) | |
| Gender male, n (%) | 42 (36.8) | 105 (60.0) | 71 (50.0) | |
| Disease duration (years), mean (SD) | 9.6 (7.0) | 11.9 (8.6) | 8.1 (7.6) | |
| Years of studies, mean (SD) | 11.0 (3.6) | 12.8 (3.1) | 14.4 (3.2) | |
| Groll comorbidity index, mean (SD) | 1.5 (2.3) | 0.6 (0.9) | 1.2 (1.4) | |
| Predominant peripheral involvement, n (%) | 95 (88.8) | 148 (88.1) | 130 (95.6) | |
| Predominant axial involvement, n (%) | 12 (11.2) | 15 (8.9) | 5 (3.7) | |
| Disease activity | ||||
| MDA state attained, n (%) | 21 (18.4) | 90 (49.5) | 59 (41.3) | <0.001 |
| DAPSA remission, n (%) | 8 (7.0) | 53 (29.1) | 24 (16.8) | <0.001 |
| DAPSA, mean (SD) | 21.2 (20.4) | 13.6 (15.5) | 15.8 (14.5) | <0.001 (0.40 (0.19 to 0.62)) |
| Swollen joint count (0–66), mean (SD) | 3.8 (11.1) | 1.2 (5.4) | 2.1 (3.7) | <0.001 (0.31 (0.10 to 0.53)) |
| Tender joint count (0–68), mean (SD) | 5.7 (10.3) | 3.3 (7.8) | 4.9 (9.1) | 0.002 (0.19 (−0.02 to 0.40)) |
| Current dactylitis, n (%) | 8 (7.1) | 8 (4.5) | 11 (7.9) | 0.416 |
| Leeds Enthesitis Index, mean (SD) | 0.6 (1.4) | 0.5 (1.2) | 0.6 (1.4) | 0.325 (0.08 (−0.14 to 0.29)) |
| Body surface area of psoriasis >5%, n (%) | 20 (17.5) | 14 (7.7) | 8 (5.6) | 0.003 (0.39 (0.17 to 0.60)) |
| Elevated C reactive protein (>5 mg/L), n (%) | 10 (8.8) | 15 (8.2) | 2 (1.4) | 0.016 (0.06 (−0.16 to 0.27)) |
| Physician global assessment of PsA (0–10), mean (SD) | 4.1 (2.5) | 2.6 (2.5) | 2.9 (2.4) | <0.001 (0.58 (0.36 to 0.79)) |
| Disease impact | ||||
| PsAID12 (0–10), mean (SD) | 4.3 (2.4) | 2.9 (2.3) | 3.3 (2.5) | <0.001 (0.50 (0.28 to 0.72)) |
| Patient global assessment of PsA (0–10), mean (SD) | 5.1 (2.6) | 3.5 (2.8) | 4.0 (3.0) | <0.001 (0.49 (0.28 to 0.71)) |
| HAQ (0–3), mean (SD) | 0.9 (0.7) | 0.5 (0.6) | 0.7 (0.7) | <0.001 (0.48 (0.26 to 0.69)) |
Lowest country GDP/capita tertile: Brazil, Turkey, Russian Federation, Romania, Estonia; middle tertile: Spain, Italy, UK, France; highest tertile: Canada, Germany, USA and Singapore.
Data were missing for predominant type of PsA (n=28), years of studies (n=23), disease duration (n=14), age (n=12), gender (n=8), current dactylitis (n=8) and PsAID12 (n=1). Percentage of male and predominant type of PsA are percentages of available data.
*Effect size (95% CI) comparing the lowest GDP/capita tertile to the two others tertiles (see also online supplemental table 1).
DAPSA, Disease Activity in PSoriatic Arthritis; GDP, gross domestic product; HAQ, Health Assessment Questionnaire; MDA, Minimal Disease Activity; PsA, Psoriatic Arthritis; PsAID, PsA Impact of Disease questionnaire.