COVID-19 Hospitalizations in Five California Hospitals
Authors: Nuño Miriam , García Yury , Rajasekar Ganesh , Pinheiro Diego , Schmidt Alec J. 
Published: February 2021

STRUCTURED ABSTRACTImportanceCharacterization of a diverse cohort hospitalized with COVID-19 in a health care system in California is needed to further understand the impact of SARS-CoV-2 and improve patient outcomes.ObjectivesTo investigate the characteristics of patients hospitalized with COVID-19 and assess factors associated with poor outcomes.DesignPatient-level retrospective cohort studySettingUniversity of California five academic hospitals.ParticipantsPatients ≥18 years old with a confirmed test result for SAR-CoV-2 virus hospitalized at five UC hospitals.ExposureConfirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by positive results on polymerase chain reaction testing of a nasopharyngeal sample among patients requiring hospital admission.Main Outcomes and MeasuresAdmission to the intensive care unit, death during hospitalization, and the composite of both outcomes.ResultsOutcomes were assessed for 4,730 patients who were discharged or died during a hospitalization. A total of 846 patients were treated at UC Davis, 1,564 UC Irvine, 1,283 UC Los Angeles, 471 UC San Diego, and 566 UC San Francisco. More than 20% of patients were ≥75 years of age (75-84: 12.3%, ≥85: 10.5%), male (56.5%), Hispanic/Latino (45.7%), and Asian (10.3%). The most common comorbidities were hypertension (35.2%), cardiac disease (33.3%), and diabetes (24.0%). The ICU admission rate was 25.2% (1194/4730), with 7.0% (329/4730) in-hospital mortality. Among patients admitted to the ICU, 18.8% (225/1194) died; 2.9% (104/3536) died without ICU admission. The rate of the composite outcome (ICU admission and/or death) was 27.4% (1,298/4,730). While controlling for comorbidities, patients of age 75-84 (OR 1.47, 95% CI: 1.11-1.93) and 85-59 (OR 1.39, 95% CI: 1.04-1.87) were more likely to experience a composite outcome than 18-34 year-olds. Males (OR 1.39, 95% CI: 1.21-1.59), and patients identifying as Hispanic/Latino (OR 1.35, 95% CI: 1.14-1.61), and Asian (OR 1.43, 95% CI: 1.23-1.82), were also more likely to experience a composite outcome than White. Patients with 5 or more comorbidities were exceedingly likely to experience a composite outcome (OR 2.74, 95% CI: 2.32-3.25).ConclusionsMales, older patients, those with pre-existing comorbidities, and those identifying as Hispanic/Latino or Asian experienced an increased risk of ICU admission and/or death.KEY POINTSQuestionWhat are the characteristics and outcomes of patients with SARS-CoV-2 infection hospitalized at five UC Health medical centers in California?FindingsIn this retrospective case series of 4,730 patients requiring hospitalization for COVID-19 in UC Health’s five medical centers, male (OR 1.41, 95% CI: 1.23-1.61), Hispanic/Latino (OR 1.35, 95% CI: 1.14-1.61), and Asian (OR 1.43, 95% CI: 1.12-1.82) were more likely to be admitted to the ICU and/or die after adjustment for age and comorbidity. ICU admission and/or death was more likely among older individuals and greater numbers of pre-existing conditions.MeaningThis study describes the experience of a large, diverse cohort of patients with COVID-19 hospitalized in five hospitals in California between December 14, 2019 and January 6, 2021.