OBJECTIVES: To ascertain if hydroxychloroquine (HCQ)/chloroquine (CLQ) and other conventional disease-modifying anti-rheumatic drugs (cDMARDs) use, and rheumatic diseases per se, may be associated with COVID-19-related risk of hospitalization and mortality. METHODS: This case-control study nested within a cohort of cDMARD users was conducted in the Lombardy, Veneto, Tuscany and Lazio regions and Reggio Emilia province. Claims databases were linked to COVID-19 surveillance registries. Risk of COVID-19-related outcomes was estimated using a multivariate conditional logistic regression analysis, comparing HCQ/CLQ vs methotrexate, vs other cDMARDs and vs non-use of these drugs. Presence of rheumatic diseases vs their absence in a non-nested population was investigated. RESULTS: 1275 cases hospitalized due to COVID-19 were matched to 12 734 controls. Compared with recent use of methotrexate, no association between HCQ/CLQ monotherapy and COVID-19 hospitalization (OR 0.83 [95%CI, 0.69-1.00]) or mortality (OR 1.19 [95%CI, 0.85-1.67]) was observed. A lower risk was found when comparing HCQ/CLQ use to the concomitant use of other cDMARDs and glucocorticoids. HCQ/CLQ was not associated with COVID-19 hospitalization as compared with non-use. An increased risk for recent use of either methotrexate monotherapy (OR 1.19 [95% CI, 1.05-1.34]) or other cDMARDs (OR 1.21 [95% CI, 1.08-1.36]) vs non-use was found. Rheumatic diseases were not associated with COVID-19-related outcomes. CONCLUSION: HCQ/CLQ use in rheumatic patients was not associated with a protective effect against COVID-19-related outcomes. Use of other cDMARDs was associated with an increased risk when compared with non-use, and, if concomitantly used with glucocorticoids, also vs HCQ/CLQ, probably to be ascribed to immunosuppressive action.
Risk of COVID-19 hospitalization and mortality in rheumatic patients treated with hydroxychloroquine or other conventional DMARDs in Italy