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Background

Understanding COVID-19 epidemiology is crucial to clinical care and to clinical trial design and interpretation.

Objective

To describe characteristics, treatment, and outcomes among patients hospitalized with COVID-19 early in the pandemic.

Methods

A retrospective cohort study of consecutive adult patients with laboratory-confirmed, symptomatic SARS-CoV-2 infection admitted to 57 US hospitals from March 1 to April 1, 2020.

Results

Of 1480 inpatients with COVID-19, median (IQR) age was 62.0 (49.4-72.9) years, 649 (43.9%) were female, and 822 of 1338 (61.4%) were non-White or Hispanic/Latino. Intensive care unit admission occurred in 575 patients (38.9%), mostly within 4 days of hospital presentation. Respiratory failure affected 583 patients (39.4%), including 284 (19.2%) within 24 hours of hospital presentation and 413 (27.9%) who received invasive mechanical ventilation. Median (IQR) hospital stay was 8 (5-15) days overall and 15 (9-24) days among intensive care unit patients. Hospital mortality was 17.7% (n=262). Risk factors for hospital death identified by penalized multivariable regression included older age; male sex; comorbidity burden; symptoms-to-admission interval; hypotension; hypoxemia; and higher white blood cell count, creatinine level, respiratory rate, and heart rate. Of 1218 survivors, 221 (18.1%) required new respiratory support at discharge and 259 of 1153 (22.5%) admitted from home required new health care services.

Conclusions

In a geographically diverse early-pandemic COVID-19 cohort with complete hospital folllow-up, hospital mortality was associated with older age, comorbidity burden, and male sex. Intensive care unit admissions occurred early and were associated with protracted hospital stays. Survivors often required new health care services or respiratory support at discharge.

Initial investigations have yielded a consensus understanding of the most common phenotypes and transmission dynamics of COVID-19 as well as preliminary identification of factors associated with adverse outcomes.1–6 Many studies, however, have been constrained by short observation periods and scarce data on hospital trajectory. Additionally, few well-designed analyses of risk factors for adverse outcomes have been conducted in diverse, multicenter patient populations. A more granular and geographically diverse nationwide analysis of the epidemiology, clinical trajectory, and heterogeneity of patients with COVID-19 is necessary to aid clinical decision-making, help clinicians situate specific cases relative to expected variation, inform clinical trial design and interpretation, and enhance health system planning.

To address these issues, we leveraged a nationwide acute care trials network to conduct an observational study of adult patients with symptomatic SARS-CoV-2 infection admitted to 57 geographically diverse US hospitals. We used high-fidelity clinical data collected during the entire hospital course (from admission to hospital discharge) to identify risk factors for in-hospital mortality and for early and late respiratory failure. We also describe patients’ illness trajectory, patterns of organ failure, therapies, and the distribution of several clinical outcomes meaningful to patients, clinicians, health system planners, and researchers.