Long-Term Hydroxychloroquine and Its Association with Covid-19 Infection, a Cohort Study from a South American Hospital

ABSTRACT

Objectives: We aimed at examining whether patients with rheumatological conditions receiving chronic hydroxychloroquine therapy are at a lower risk of developing SARS-CoV-2 infection than those not receiving hydroxychloroquine. Method(s) This historical cohort study included information of all patients aged 18 years or older with rheumatoid arthritis, systemic lupus erythematosus, or associated rheumatological conditions (based on International Classification of Diseases, 10th edition, diagnostic codes). A propensity score was calculated for each patient, and each patientwho was receiving hydroxychloroquine was matched to two patients who were not receiving hydroxychloroquine (controls). The primary endpoint was the proportion of patients with PCR-confirmed SARS-CoV-2 infection among those receiving chronic hydroxychloroquine versus the propensity-matched patients not receiving chronic hydroxychloroquine in 2021. Result(s) 322 patients receiving hydroxychloroquine and 645 patients not receiving hydroxychloroquine were included in the primary analysis. The incidence of active SARS-CoV-2 infections during the study period did not differ between patients receiving hydroxychloroquine and patients not receiving hydroxychloroquine ( [0 3%] vs 78 [0 4%] of 21406;odds ratio 0 79, 95% CI 0 52-1 20, p = 0 27). There were no significant differences in secondary outcomes between the two groups of patients who developed active SARS-CoV-2 infection. For all patients in the study, overall mortality was lower in the hydroxychloroquine group than in the group of patients who did not receive hydroxychloroquine (odds ratio hydroxychloroquine was not associated with the development of active SARS-CoV-2 infection (odds ratio 0 79, 95% CI 0 51-1 42) Conclusion(s) Hydroxychloroquine was not associated with a protective effect against SARS-CoV-2 infection in a large group of patients with rheumatological conditions.