3219 hospitalised patients with COVID-19 in Southeast Michigan: a retrospective case cohort study

OBJECTIVE: To report the clinical characteristics of patients hospitalised with COVID-19 in Southeast Michigan. DESIGN: Retrospective cohort study. SETTING: Eight hospitals in Southeast Michigan. PARTICIPANTS: 3219 hospitalised patients with a positive SARS-CoV-2 infection by nasopharyngeal PCR test from 13 March 2020 until 29 April 2020. MAIN OUTCOMES MEASURES: Outcomes were discharge from the hospital or in-hospital death. Examined predictors included patient demographics, chronic diseases, home medications, mechanical ventilation, in-hospital medications and timeframe of hospital admission. Multivariable logistic regression was conducted to identify risk factors for in-hospital mortality. RESULTS: During the study period, 3219 (90.4%) patients were discharged or died in the hospital. The median age was 65.2 (IQR 52.6–77.2) years, the median length of stay in the hospital was 6.0 (IQR 3.2–10.1) days, and 51% were female. Hypertension was the most common chronic disease, occurring in 2386 (74.1%) patients. Overall mortality rate was 16.0%. Blacks represented 52.3% of patients and had a mortality rate of 13.5%. Mortality was highest at 18.5% in the prepeak hospital COVID-19 volume, decreasing to 15.3% during the peak period and to 10.8% in the postpeak period. Multivariable regression showed increasing odds of in-hospital death associated with older age (OR 1.04, 95% CI 1.03 to 1.05, p<0.001) for every increase in 1 year of age and being male (OR 1.47, 95% CI 1.21 to 1.81, p<0.001). Certain chronic diseases increased the odds of in-hospital mortality, especially chronic kidney disease. Administration of vitamin C, corticosteroids and therapeutic heparin in the hospital was associated with higher odds of death. CONCLUSION: In-hospital mortality was highest in early admissions and improved as our experience in treating patients with COVID-19 increased. Blacks were more likely to get admitted to the hospital and to receive mechanical ventilation, but less likely to die in the hospital than whites.