Abstract: Federated Electronic Medical Record Network Shailendra Singh, Ahmad Khan, Monica Chowdhry, Arka Chatterjee Authors Shailendra Singh M.D 1. Division of Gastroenterology, West Virginia University Health Sciences Center Charleston Division, Charleston, WV. 2. Charleston Area Medical Center Health System, Charleston, WV. Ahmad Khan M.D Department of Medicine, West Virginia University Health Sciences Center Charleston Division, Charleston, WV. Monica Chowdhry M.D Department of Medicine, West Virginia University Health Sciences Center Charleston Division, Charleston, WV. Arka Chatterjee M.D Division of Cardiovascular Disease, University of Alabama at Birmingham. medRxiv preprint doi: https://doi.org/10.1101/2020.05.12.20099028; this version posted May 19, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license . NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice. Outcomes of Hydroxychloroquine Treatment Among Hospitalized COVID-19 Patients in the United States- Real-World Evidence From a Shailendra Singh M.D Charleston Area Medical Center Health System, Charleston, WV Email: Shail121@gmail.com Phone no: 304-342-0821 Fax: 304-345-6679 Acknowledgment We acknowledge the West Virginia Clinical and Translational Science Institute to provide us access, and training to the TriNETX global healthcare network. We also acknowledge the TriNETX (Cambridge, MA, USA) healthcare network for design assistance to complete this project. The authors received no financial support or grants for the research, authorship, and publication of this article. Shailendra Singh, Ahmad Khan, Monica Chowdhry and Arka Chatterjee declare that they have no conflict of interest. medRxiv preprint doi: https://doi.org/10.1101/2020.05.12.20099028; this version posted May 19, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license . Corresponding Author On March 28, 2020, in response to the rapidly accelerating COVID-19 pandemic, U.S FDA issued emergency use authorization for hydroxychloroquine (HCQ) in hospitalized COVID-19 patients based on limited in-vitro and anecdotal clinical data1,2. Analysis of the accumulated real-world data utilizing electronic medical records (EMR) could indicate HCQ therapy benefits as we await the results of clinical trials. However, any such analysis of retrospective observational data should account for variables such as demographics and comorbidities that could affect treatment strategies or outcomes. Therefore, we report the outcomes of HCQ treatment in a propensity-matched cohort of COVID-19 hospitalized patients. Methods and Findings Using the TriNetX (Cambridge, MA, USA), a global federated health research network, we performed a real-time search and analysis of EMR of more than 40 million patients from 34 healthcare organizations (HCOs) in the United States. TriNETX recently fast-tracked data inflow to incorporate COVID-19 specific diagnosis and terminology following the World Health Organization (WHO) and Centers for Disease Control (CDC) criteria. As a federated network,..