Laboratory findings associated with severe illness and mortality among hospitalized individuals with coronavirus disease 2019 in Eastern Massachusetts

IMPORTANCE: The coronavirus disease 2019 (COVID-19) pandemic has placed unprecedented stress on health systems across the world, and reliable estimates of risk for adverse hospital outcomes are needed. OBJECTIVE: To quantify admission laboratory and comorbidity features associated with critical illness and mortality risk across 6 Eastern Massachusetts hospitals. DESIGN: Retrospective cohort study using hospital course, prior diagnoses, and laboratory values. SETTING: Emergency department and inpatient settings from 2 academic medical centers and 4 community hospitals. PARTICIPANTS: All individuals with hospital admission and positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by PCR testing across these 6 hospitals through June 5, 2020. EXPOSURE: Coronavirus 2 (SARS-CoV-2). MAIN OUTCOME MEASURES: Severe illness defined by ICU admission, mechanical ventilation, or death. RESULTS: Among 2,511 hospitalized individuals who tested positive for SARS-CoV-2 (of whom 50.9% were male, 53.9% white, and 27.0% Hispanic, with mean age 62.6 years), 215 (8.6%) were admitted to the ICU, 164 (6.5%) required mechanical ventilation, and 292 (11.6%) died. L1-regression models developed in 3 of these hospitals yielded area under ROC curve (AUC) of 0.807 for severe illness and 0.847 for mortality in the 3 held-out hospitals. In total, 212/292 (78%) of the deaths occurred in the highest-risk mortality quintile. CONCLUSIONS AND RELEVANCE: In this cohort, specific admission laboratory studies in concert with sociodemographic features and prior diagnosis facilitated risk stratification among individuals hospitalized for COVID-19. FUNDING: 1R56MH115187-01 TRIAL REGISTRATION: None