Demographic and clinical characteristics of study population
| HCQ users (n=112) | Non-HCQ users (n=802) | P value | |
| Age (mean±SD) | 57.3±14.2 | 54.5±16 | 0.06 |
| Female | 96 (85.7%) | 528 (65.8%) | <0.0001 |
| Disease duration (mean±SD) | 11.4±10 | 13.4±9 | 0.07 |
| Diagnosis | |||
| Rheumatoid arthritis | 79 (70.6%) | 401 (50%) | <0.0001 |
| Spondyloarthritis | 8 (7.1%) | 307 (38.2%) | <0.0001 |
| Connective tissue diseases | 21 (18.7%) | 52 (6.5%) | <0.0001 |
| Other | 4 (3.6%) | 42 (5.3%) | 0.64 |
| Concomitant bDMARD | 50 (44.6%) | 605 (75.4%) | <0.0001 |
| Concomitant corticosteroids | 70 (62.5%) | 253 (31.5%) | <0.0001 |
| Comorbidities (≥1) | 39 (34.8%) | 302 (37.6%) | 0.60 |
| COVID-19 | |||
| Contagion prevention | 93 (83%) | 700 (87.2%) | 0.23 |
| Treatment discontinuation | 4 (3.6%) | 42 (5.2%) | 0.54 |
| Definite contact with COVID-19 positive subjects | 2 (1.8%) | 14 (1.7%) | 0.90 |
| COVID-19 positive swab | 1 (0.89%) | 5 (0.62%) | 0.64 |
| Respiratory symptoms (no swab) | 18 (16%) | 117 (14.6%) | 0.67 |
P value was calculated by using Fisher’s test for categorical variables and t-test for continuous variables. Respiratory symptoms, at least one between fever >37.5°C, cough, or dyspnoea of recent onset.
bDMARD, biologic disease-modifying antirheumatic drugs; HCQ, hydroxychloroquine.