AbstractBackgroundCoronavirus Disease 2019 (COVID-19) has become a major global issue with rising the number of infected individuals and mortality in recent months. Among all therapeutic approaches, arguments have raised about hydroxychloroquine (HCQ) efficacy in the treatment of COVID-19. We aimed to overcome the controversies regarding the effectiveness of hydroxychloroquine in the treatment of COVID-19, using a systematic review and meta-analysis.MethodsA systematic search was performed in PubMed, Scopus, Embase, Cochrane Library, Web of Science, Google Scholar and medRxiv pre-print database using all available MeSH terms for COVID-19 and hydroxychloroquine. Two authors selected and assessed the quality of studies independently using related checklists. Data have been extracted from included studies and analyzed using CMA v. 2.2.064. heterogeneity was also assessed using the I-squared test. We also conducted different sensitivity analyses to examine the effect of studies that greatly influence the results.ResultsOut of 14 studies entered into our systematic review, 12 studies including seven comparative studies with control group and five observational studies containing 3,428 participants have entered into the study. The results of the meta-analysis on comparative studies indicated no significant clinical effectiveness (negative in RT-PCR evaluation) for HCQ regimen in the treatment of COVID-19 in comparison to control group (RR: 1.04, 95% CI, 0.83-1.31). The same result was observed for the combination of HCQ+azithromycin (RR: 2.15, 95% CI, 0.31-14.77). Approximately 1.7 times higher mortality rate was observed among the HCQ regimen group in comparison to control group (RR: 1.73, 95% CI, 1.06-2.81), which was not related to the age differences according to meta-regression analysis (P=0.305). No substantial difference was observed for disease exacerbation (RR: 1.87, 95% CI, 0.28-12.36) between HCQ group and controls. Also, radiological findings significantly improved in the HCQ group (OR: 0.32, 95% CI, 0.11-0.98). Odds of known HCQ adverse effects (diarrhea, vomiting, blurred vision, rash, headache, etc.) occurred in the HCQ regimen group was approximately 3.5 times of control group (OR: 3.55, 95% CI, 1.61-7.82), but no substantial differences were found regarding intubation odds between HCQ group and control group (OR: 2.11, 95% CI, 0.31-14.03).ConclusionThis systematic review and meta-analysis not only indicated no clinical benefits regarding HCQ treatment with/without azithromycin for COVID-19 patients, but the higher mortality rate and frequency of known HCQ adverse effects were observed for the HCQ regimen group. However, due to that most of the studies were non-randomized and results were not homogenous, selection bias was unavoidable and further large randomized clinical trials following comprehensive meta-analysis should be taken into account in order to achieve more reliable findings.