Abstract: RESEARCH Wei Tang,1,2 Zhujun Cao,3 Mingfeng Han,4 Zhengyan Wang,5 Junwen Chen,6 Wenjin Sun,7 Yaojie Wu,8 Wei Xiao,9 Shengyong Liu,10 Erzhen Chen,11 Wei Chen,1,2 Xiongbiao Wang,12 Jiuyong Yang,13 Jun Lin,14 Qingxia Zhao,15 Youqin Yan,16 Zhibin Xie,17 Dan Li,18 Yaofeng Yang,19 Leshan Liu,20 Jieming Qu,1,2 Guang Ning,21 Guochao Shi,1,2 Qing Xie3 For numbered affiliations see end of the article Correspondence to: Q Xie xieqingrjh@163.com (ORCID 0000-0002-2582-8803) Additional material is published online only. To view please visit the journal online. Cite this as: BMJ 2020;369:m1849 http://dx.doi.org/10.1136/bmj.m1849 Accepted: 6 May 2020 ABSTRACT OBJECTIVE To assess the efficacy and safety of hydroxychloroquine plus standard of care compared with standard of care alone in adults with coronavirus disease 2019 (covid-19). DESIGN Multicentre, open label, randomised controlled trial. SETTING 16 government designated covid-19 treatment centres in China, 11 to 29 February 2020. PARTICIPANTS 150 patients admitted to hospital with laboratory confirmed covid-19 were included in the intention to treat analysis (75 patients assigned to hydroxychloroquine plus standard of care, 75 to standard of care alone). INTERVENTIONS Hydroxychloroquine administrated at a loading dose of 1200 mg daily for three days followed by a maintenance dose of 800 mg daily (total treatment duration: two or three weeks for patients with mild to moderate or severe disease, respectively). MAIN OUTCOME MEASURE Negative conversion of severe acute respiratory syndrome coronavirus 2 by 28 days, analysed according to the intention to treat principle. Adverse events were analysed in the safety population in which hydroxychloroquine recipients were WHAT IS ALREADY KNOWN ON THIS TOPIC The pandemic of coronavirus disease 2019 (covid-19) imposes a substantial burden on individuals, communities, healthcare facilities, markets, and governments globally No specific treatment has been approved for covid-19, and no vaccine exists to prevent infection with SARS-CoV-2 During the urgent pandemic, media headlines encourage the use of drugs without solid evidence but ignore the side effects of these drugs WHAT THIS STUDY ADDS In this randomised clinical trial of patients with mainly persistent mild to moderate covid-19, exposure to hydroxychloroquine led to a similar probability of virus elimination to the current standard of care Adverse events, mostly gastrointestinal, were significantly higher in patients who received hydroxychloroquine Overall, the results do not support the use of hydroxychloroquine in patients with persistent mild to moderate covid-19 the bmj | BMJ 2020;369:m1849 | doi: 10.1136/bmj.m1849 participants who received at least one dose of hydroxychloroquine and hydroxychloroquine nonrecipients were those managed with standard of care alone. RESULTS Of 150 patients, 148 had mild to moderate disease and two had severe disease. The mean duration from symptom onset to randomisation was 16.6 (SD 10.5; range 3-41) days. A total of 109 (73%) patients (56 standard of care; 53 standard of care plus hydroxychloroquine) had negative conversion well before 28 days, and the remaining 41 (27%) patients (19 standard of care; 22 standard of care plus hydroxychloroquine) were censored as they did not reach negative conversion of virus. The probability of negative conversion by 28 days in the standard of care plus hydroxychloroquine group was 85.4% (95% confidence interval 73.8% to 93.8%),..