Effects of dexamethasone use on viral clearance among patients with COVID-19: a multicenter cohort study

Objectives: This study explored the outcomes and predictors of early viral clearance among patients with COVID-19. Methods: This study recruited consecutive patients from March 1, 2020 to July 31, 2021. Early viral clearance was defined as having a duration from symptom onset to successive detection of SARS-CoV-2 polymerase chain reaction cycle threshold (Ct) value of ≥30 within 10 days. Results: Among the 239 enrolled patients, 54.4% (130 patients) had early viral clearance. A multivariate logistic regression analysis identified that dexamethasone use and day 1 Ct values were independent factors associated with late viral clearance. Patients with mild-moderate severity and who received dexamethasone therapy had a longer time to viral clearance than those who did not receive dexamethasone (17.2 ± 1.8 days vs 12.3 ± 1.1 days, P = 0.018). Patients with severe-critical severity had a similar duration from symptom onset to Ct value ≥30, regardless of dexamethasone therapy (18.3 ± 0.9 days vs 16.7 ± 4.7 days, P = 0.626). Conclusion: The study revealed that dexamethasone therapy and Ct values are independent predictors of late viral clearance. Patients with severe disease course due to older age, increased number of comorbidities, and worse clinical outcomes experienced delayed viral clearance.