Characteristics of patients discharged and readmitted after COVID-19 hospitalisation within a large integrated health system in the United States.

Background Limited studies have explored post-discharge outcomes following Coronavirus Disease 2019 (COVID-19) hospitalisation. We sought to characterise patients discharged following a COVID-19 hospitalisation within a large integrated health system in the United States. Methods We performed a retrospective study of 2180 COVID-19 patients discharged between 1 April 2020 and 31 July 2020. The primary endpoint was all-cause observation stay or inpatient readmission within 30 days from discharge. Bivariate and multivariable logistic regression analyses were performed to estimate the association between key socio-demographic and clinical characteristics with risk of 30-day readmission. Results The 30-day readmission rate was 7.6% (n = 166); 30-day mortality rate was 1% (n = 19). Most readmissions were respiratory-related (58%) and occurred at a median time of 5 days post discharge. Adjusted models showed that prior hospitalisations (Odds Ratio = 2.36, [95% Confidence Interval: 1.59-3.50]), chronic pulmonary disease (1.57 [1.09-2.28]), and discharge to home health (1.46 [1.01-2.11]) were significantly associated with 30-day readmission. Longer duration from diagnosis to index admission was borderline associated with lower odds of readmission (0.95 [0.91-1.00]). Conclusion Readmission and mortality rates for COVID-19 following discharge are low. Most readmissions occur early and are due to respiratory causes and may reflect the prolonged acute disease course.