Machine Learning Techniques to Explore Clinical Presentations of COVID-19 Severity and to Test the Association With Unhealthy Opioid Use: Retrospective Cross-sectional Cohort Study

Hale M Thompson   ^{1, 2} , MA, MSc, PhD ;   Brihat Sharma   ¹ , MSc ;   Dale L Smith   ¹ , PhD ;   Sameer Bhalla   ³ , MD ;   Ihuoma Erondu   ¹ , MD ;   Aniruddha Hazra   ⁴ , MD ;   Yousaf Ilyas   ¹ ;   Paul Pachwicewicz   ¹ , MSc ;   Neeral K Sheth   ⁵ , MD ;   Neeraj Chhabra   ⁶ , MSc, MD ;   Niranjan S Karnik   ¹ , MD, PhD ;   Majid Afshar   ⁷ , MSc, MD

¹ Section of Community Behavioral Health, Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, IL, United States

² Center for Education, Research, and Advocacy, Department of Social and Behavioral Research, Howard Brown Health, Chicago, IL, United States

³ Department of Internal Medicine, Rush University Medical Center, Chicago, IL, United States

⁴ Section of Infectious Diseases and Global Health, Department of Medicine, University of Chicago, Chicago, IL, United States

⁵ Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, IL, United States

⁶ Department of Emergency Medicine, Rush University Medical College, Rush University Medical Center, Chicago, IL, United States

⁷ Division of Pulmonary and Critical Care, Department of Medicine, School of Medicine and Public Health, University of Wisconsin, Madison, WI, United States