Comment on 'Baseline use of hydroxychloroquine in systemic lupus erythematosus does not preclude SARS-CoV-2 infection and severe COVID-19' by Konig et al. Long-term exposure to hydroxychloroquine or chloroquine and the risk of hospitalisation with COVID-19: a nationwide, observational cohort study in 54 873 exposed individuals and 155 689 matched unexposed individuals in France

We have read the recent report by Konig et al 1 with great interest where they described the clinical course of COVID-19 in 80 patients with systemic lupus erythematosus. The frequency of hospitalisation with COVID-19 did not differ between individuals using a synthetic antimalarial drug (AMD) and non-users. The objective of this report was to examine the association of long-term synthetic AMD exposure with hospitalisation with COVID-19 in a larger population in France.\n\nWe did a nationwide, retrospective, matched ‘exposed/unexposed’ cohort study using information from the French national health data system (online supplementary methods).2 All individuals who had six reimbursements of synthetic AMD (hydroxychloroquine (HCQ) or chloroquine) within the 12-month period preceding study entry (15 February 2020) were included. For each exposed individual, we randomly selected, from the entire French population, up to three unexposed individuals matched on age, sex, department of residence and complementary universal health insurance. The underlying diseases related to synthetic AMD exposure were recorded, as well as comorbidities and consumption of oral steroids (online supplementary tables 1 and 2). Our study was based on data available on hospital discharges as of 7 June 2020 (online supplementary methods). On this date, 83 445 patients with hospitalisation with COVID-19 have been reported, and 14 566 …