Risk factors associated with the need for oxygen therapy in patients with COVID-19

Respiratory failure is the major cause of death in patients with coronavirus disease (COVID-19). Data on factors affecting the need for oxygen therapy in early-stage COVID-19 are limited. This study aimed to evaluate the factors associated with the need for oxygen therapy in patients with COVID-19.This is a retrospective study of consecutive COVID-19 patients who were hospitalized between February 27 and June 28, 2020, in South Korea. Logistic regression analyses were performed to identify the factors associated with the need for oxygen therapy.Of the 265 patients included in the study, 26 (9.8%) received oxygen therapy, and 7 of these patients (29.2%) were transferred to a step-up facility, and 3 (11.5%) died. The median age of all patients was 46 years (IQR, 30-60 years), and the median modified early warning score at admission was 1 (IQR, 1-2). In a multivariate logistic regression analysis, being a current smoker (odds ratio [OR] 7.641, 95% confidence interval [CI] 1.686-34.630, P = .008), heart rate (OR 1.053, 95% CI 1.010-1.097, P = .014), aspartate aminotransferase values (OR 1.049, 95% CI 1.008-1.092, P = .020), blood urea nitrogen levels (OR 1.171, 95% CI 1.073-1.278, P < .001), and chest radiographic findings (OR 3.173, 95% CI 1.870-5.382, P < .001) were associated with oxygen therapy.In patients with less severe COVID-19, the need for oxygen therapy is affected by smoking and elevated values of aspartate aminotransferase and blood urea nitrogen. Further research is warranted on the risk factors for deterioration in COVID-19 to efficiently allocate medical resources.