Risk Factors Associated With In-Hospital Mortality in a US National Sample of Patients With COVID-19.

Importance: Coronavirus disease 2019 (COVID-19) has infected more than 8.1 million US residents and killed more than 221 000. There is a dearth of research on epidemiology and clinical outcomes in US patients with COVID-19.

Objectives: To characterize patients with COVID-19 treated in US hospitals and to examine risk factors associated with in-hospital mortality.

Design, Setting, and Participants: This cohort study was conducted using Premier Healthcare Database, a large geographically diverse all-payer hospital administrative database including 592 acute care hospitals in the United States. Inpatient and hospital-based outpatient visits with a principal or secondary discharge diagnosis of COVID-19 (International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis code, U07.1) between April 1 and May 31, 2020, were included.

Exposures: Characteristics of patients were reported by inpatient/outpatient and survival status. Risk factors associated with death examined included patient characteristics, acute complications, comorbidities, and medications.

Main Outcomes and Measures: In-hospital mortality, intensive care unit (ICU) admission, use of invasive mechanical ventilation, total hospital length of stay (LOS), ICU LOS, acute complications, and treatment patterns.

Results: Overall, 64 781 patients with COVID-19 (29 479 [45.5%] outpatients; 35 302 [54.5%] inpatients) were analyzed. The median (interquartile range [IQR]) age was 46 (33-59) years for outpatients and 65 (52-77) years for inpatients; 31 968 (49.3%) were men, 25 841 (39.9%) were White US residents, and 14 340 (22.1%) were Black US residents. In-hospital mortality was 20.3% among inpatients (7164 patients). A total of 5625 inpatients (15.9%) received invasive mechanical ventilation, and 6849 (19.4%) were admitted to the ICU. Median (IQR) inpatient LOS was 6 (3-10) days. Median (IQR) ICU LOS was 5 (2-10) days. Common acute complications among inpatients included acute respiratory failure (19 706 [55.8%]), acute kidney failure (11 971 [33.9%]), and sepsis (11 910 [33.7%]). Older age was the risk factor most strongly associated with death (eg, age ≥80 years vs 18-34 years: odds ratio [OR], 16.20; 95% CI, 11.58-22.67; P < .001). Receipt of statins (OR, 0.60; 95% CI, 0.56-0.65; P < .001), angiotensin-converting enzyme inhibitors (OR, 0.53; 95% CI, 0.46-0.60; P < .001), and calcium channel blockers (OR, 0.73; 95% CI, 0.68-0.79; P < .001) was associated with decreased odds of death. Compared with patients with no hydroxychloroquine or azithromycin, patients with both azithromycin and hydroxychloroquine had increased odds of death (OR, 1.21; 95% CI, 1.11-1.31; P < .001).

Conclusions and Relevance: In this cohort study of patients with COVID-19 infection in US acute care hospitals, COVID-19 was associated with high ICU admission and in-hospital mortality rates. Use of statins, angiotensin-converting enzyme inhibitors, and calcium channel blockers were associated with decreased odds of death. Understanding the potential benefits of unproven treatments will require future randomized trials.