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Alison Dillman,1 Michael J Zoratti,2 Jay JH Park,3 Grace Hsu,2 Louis Dron,2 Gerald Smith,2 Ofir Harari,2 Craig R Rayner,4 Noor-E Zannat,2 Alind Gupta,2 Eric Mackay,5 Paul Arora,6 Zelyn Lee,7 Edward J Mills2 1School of Public Health, Faculty of Medicine, Imperial College London, London, England; 2Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada; 3Department of Experimental Medicine, University of British Columbia, Vancouver, British Columbia, Canada; 4Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Australia; 5Department of Statistical Sciences, University of Toronto, Toronto, Canada; 6Dalla Lana School of Public Health, University of Toronto, Toronto, Canada; 7Department of Physiology & Department of Neuroscience, University of Toronto, Toronto, CanadaCorrespondence: Jay JH Park Tel +1 604 294-3823Email jayhpark1@alumni.ubc.caPurpose: A multitude of randomized controlled trials (RCTs) have emerged in response to the novel coronavirus disease (COVID-19) pandemic. Understanding the distribution of trials among various settings is important to guide future research priorities and efforts. The purpose of this review was to describe the emerging evidence base of COVID-19 RCTs by stages of disease progression, from pre-exposure to hospitalization.Methods: We collated trial data across international registries: ClinicalTrials.gov; International Standard Randomised Controlled Trial Number Registry; Chinese Clinical Trial Registry; Clinical Research Information Service; EU Clinical Trials Register; Iranian Registry of Clinical Trials; Japan Primary Registries Network; German Clinical Trials Register (up to 7 October 2020). Active COVID-19 RCTs in international registries were eligible for inclusion. We extracted trial status, intervention(s), control, sample size, and clinical context to generate descriptive frequencies, network diagram illustrations, and statistical analyses including odds ratios and the Mann–Whitney U-test.Results: Our search identified 11503 clinical trials registered for COVID-19 and identified 2388 RCTs. After excluding 45 suspended RCTs and 480 trials with unclear or unreported disease stages, 1863 active RCTs were included and categorized into four broad disease stages: pre-exposure (n=107); post-exposure (n=208); outpatient treatment (n=266); hospitalization, including the intensive care unit (n=1376). Across all disease stages, most trials had two arms (n=1500/1863, 80.52%), most often included (hydroxy)chloroquine (n=271/1863, 14.55%) and were US-based (n=408/1863, 21.90%). US-based trials had lower odds of including (hydroxy)chloroquine than trials in other countries (OR: 0.63, 95% CI: 0.45– 0.90) and similar odds of having two arms compared to other geographic regions (OR: 1.05, 95% CI: 0.80– 1.38).Conclusion: There is a marked difference in the number of trials across settings, with limited studies on non-hospitalized persons. Focus on pre- and post-exposure, and outpatients, is worthwhile as a means of reducing infections and lessening the health, social, and economic burden of COVID-19.Keywords: COVID-19, novel coronavirus 2019, systematic review, randomized controlled trials