Comparison of patient characteristics, RA disease activity measures and treatment-related variables in the QUEST–RA study in “high GDP” and “low GDP” countries
| Total | “High GDP” countries | “Low GDP” countries | p Value* | |
| N | 6004 | 3719 | 2285 | |
| Patient characteristics | ||||
| Female, % | 79% | 75% | 86% | <0.001 |
| Age, years, mean | 56 | 58 | 54 | <0.001 |
| Education, years, median | 11 | 11 | 11 | 0.16 |
| Smoking now, % | 17% | 19% | 14% | <0.001 |
| BMI, mean | 26 | 26 | 26 | 0.63 |
| Disease duration, years, mean | 11 | 11 | 11 | 0.038 |
| Disease activity measures | ||||
| DAS28 (0–9.1), mean | 4.2 | 3.7 | 5.1 | <0.001 |
| Physician | ||||
| SJC (0–28), median | 2 | 1 | 4 | <0.001 |
| TJC (0–28), median | 4 | 2 | 8 | <0.001 |
| Physician global (0–10), median | 2.4 | 1.7 | 3.7 | <0.001 |
| Patient self-report | ||||
| HAQ physical function (0–3) median | 0.88 | 0.75 | 1.3 | <0.001 |
| Pain VAS (0–10), median | 4.1 | 3.3 | 4.9 | <0.001 |
| Patient global VAS (0–10), median | 4.2 | 3.2 | 4.9 | <0.001 |
| Psychological HAQ (0–3), mean | 0.82 | 0.7 | 1.3 | <0.001 |
| Laboratory/imaging | ||||
| ESR, median | 22 | 18 | 30 | <0.001 |
| RF-positive, % | 74% | 72% | 76% | 0.001 |
| Erosive disease, % | 63% | 58% | 72% | <0.001 |
| In patients with disease duration ⩽2 years | 23% | 40% | <0.001 | |
| In patients with disease duration ⩾10 years | 79% | 84% | 0.001 | |
| Treatment-related variables | ||||
| Patients taking DMARD ever, % | 97% | 97% | 97% | 0.75 |
| Delay to start a DMARD, months, median | 9 | 9 | 9 | 0.063 |
| No of DMARD ever taken, mean | 2.7 | 2.8 | 2.5 | <0.001 |
| Methotrexate ever, % of patients | 85% | 86% | 84% | <0.001 |
| Methotrexate now, % of patients | 63% | 63% | 62% | 0.36 |
| Prednisone ever, % of patients | 71% | 66% | 80% | <0.001 |
| Prednisone now, % of patients | 49% | 42% | 60% | <0.001 |
| Biologicals ever, % of patients | 23% | 31% | 9.4% | <0.001 |
| Biologicals now, % of patients | 18% | 25% | 7.5% | <0.001 |
| Any DMARD, % of disease duration | 72% | 75% | 67% | 0.085 |
| Methotrexate, % of disease duration | 31% | 32% | 30% | 0.18 |
| Biologicals, % of disease duration | 3.9% | 5.6% | 1.8% | 0.001 |
*Unadjusted p values are presented. BMI, body mass index; DAS28, disease activity score in 28 joints; DMARD, disease-modifying antirheumatic drug; ESR, erythrocyte sedimentation rate; GDP, gross domestic product; HAQ, health assessment questionnaire; RA, rheumatoid arthritis; RF, rheumatoid factor; SJC, swollen joint count; TJC, tender joint count; VAS, visual analogue scale.