OBJECTIVES : Oxygen therapy is critical in severe COVID-19 patients. Factors that impact the oxygen use in severe COVID-19 patients are important to understand. This study aims to identify the factors such as co-morbidities, length of stay, post-discharge oxygen use, and rehospitalization in COVID-19 patients with oxygen therapy.

METHODS : We identified hospitalized patients diagnosed with COVID-19 from 01 April 2020 to 31 December 2020 using Optum’s de-identified US administrative claims database. Index date was date of first inpatient COVID-19 diagnosis. Included patients had evidence of oxygen therapy during their hospital stay; pregnant patients were excluded. Patients were observed 12-months pre-index to capture demographics and comorbidities; and were observed for at least 3 months post-discharge to assess the outcomes.

RESULTS : A total of 104,456 hospitalized patients with COVID-19 were identified; 16,492 (15.8%) had evidence of oxygen therapy use during hospitalization. Mean (SD) age was 68.8 (12.1) years, 48.3% were males. During baseline, the most frequent (top 5) comorbidities were hypertension (83.7%), other cardiovascular disease (69.5%), diabetes mellitus (52.2%), obesity (51.7%), and kidney disease (38.7%). Respiratory-related comorbidities such as COPD, other pulmonary disease, and asthma were found in 34.0%, 32.9%, and 16.0% of patients, respectively. Hospital length of stay was <7 days, 7-14 days and >14 days for 30.6%, 29.1%, and 17.8% of patients, respectively; 5.0% of patients had evidence of home-based oxygen therapy after discharge. Overall, 28.3% of patients were rehospitalized within 60 days post-discharge regardless of their home-based oxygen use.

CONCLUSIONS : Comorbidities were prevalent among hospitalized patients with COVID-19 using oxygen therapy; and rehospitalization was common. Further analysis is needed to understand the impact of comorbid conditions on rehospitalization in patients with severe COVID-19 requiring hospitalization and oxygen therapy. Evidence of oxygen therapy was low, suggesting oxygen use is under-reported in administrative claims data, future studies using EHR data may be appropriate.