Abstract: Journal of Clinical Medicine Review COVID-19 Infection in Rheumatic Patients on Chronic Antimalarial Drugs: A Systematic Review and Meta-Analysis Isabela Landsteiner de Sampaio Amêndola 1, *, Jonathan Aires Pinheiro 2,3 , Pedro Póvoa 4,5,6 , Vicente Cés de Souza Dantas 7,8 and Rodrigo Bernardo Serafim 9,10 1 2 3 4 5 6 7 8 9 10 * Citation: Landsteiner de Sampaio Amêndola, I.; Aires Pinheiro, J.; Póvoa, P.; Cés de Souza Dantas, V.; Serafim, R.B. COVID-19 Infection in Rheumatic Patients on Chronic Antimalarial Drugs: A Systematic Review and Meta-Analysis. J. Clin. Med. 2022, 11, 6865. https:// doi.org/10.3390/jcm11226865 Academic Editor: Shunsuke Mori Marilia Medical School, Marília 17519-030, Brazil Health Sciences Center, University of Fortaleza, Fortaleza 60811-905, Brazil Siupe Primary Care Facility, São Gonçalo do Amarante 62670-000, Brazil NOVA Medical School, New University of Lisbon, 1169-056 Lisboa, Portugal Center for Clinical Epidemiology and Research Unit of Clinical Epidemiology, Odense University Hospital, 5000 Odense, Denmark Intensive Care Department, Hospital de São Francisco Xavier, CHLO, 1150-199 Lisboa, Portugal Instituto D’or de Pesquisa e Ensino, Rio de Janeiro 22281-100, Brazil Clinical Research Team, Hospital Naval Marcílio Dias, Rio de Janeiro 22281-100, Brazil Intensive Care Unit, Hospital Copa D’or, Rio de Janeiro 22031-011, Brazil Internal Medicine Department, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil Correspondence: isa.lands@hotmail.com; Tel.: +55-(19)99190-9911 Abstract: The ongoing chronic use of hydroxychloroquine or chloroquine (HCQ/CQ) in rheumatic patients might impact their outcomes after a SARS-CoV-2 infection. Therefore, we sought to assess the mortality in rheumatic patients with chronic HCQ/CQ use who developed a COVID-19 infection through a comparison between individuals chronically using HCQ/CQ with those not taking these drugs. We performed a systematic review and meta-analysis of studies on PubMed, Embase, and Cochrane Central. We included full-length reports, prospective observational cohorts, and clinical trials of adult patients (aged ≥ 18 years) who were diagnosed with a COVID-19 infection. Case studies, case series, letters, comments, and editorials were excluded. The main outcome was all-cause mortality. This study is registered with PROSPERO (CRD42022341678). We identified 541 studies, of which 20 studies were included, comprising 236,997 patients. All-cause mortality was significantly lower in patients with prior chronic use of HCQ/CQ compared to those with no previous usage (OR 0.76; 95% CI 0.62–0.94; p = 0.01). There was a considerably lower incidence of hospitalization among patients with chronic HCQ/CQ use compared to their counterparts without HCQ/CQ usage (OR 0.80; 95% CI 0.65–0.99; p = 0.04). All-cause mortality and hospitalization were significantly lower in rheumatic patients with chronic HCQ/CQ use who developed a COVID-19 infection. Received: 24 October 2022 Accepted: 18 November 2022 Published: 21 November 2022 Keywords: coronavirus disease-19; severe acute respiratory syndrome coronavirus 2; chloroquine; hydroxychloroquine; rheumatic diseases Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative..