To the Editor—Coronavirus disease 2019 (COVID-19) is a newly emerged disease that is now spreading globally. Severe acute respiratory syndrome (SARS)–associated coronavirus 2 (SARS-CoV-2) has been identified as the causative agent, which has affected more than 6 million patients in over 200 countries, causing 400 000 deaths between December 2019 and June 2020. So far, there has been no proven effective therapies for COVID-19. Since proinflammatory cytokine storms may play a prominent role in the pathogenesis of COVID-19, corticosteroid use was recommended by Chinese guidelines [1]. However, routinely administering systemic corticosteroids was not suggested by the World Health Organization for patients with COVID-19 because of potential adverse outcomes such as prolonged viral shedding duration, as observed in SARS [2, 3]. In our previous paper, patients with early RNA clearance had a lower prevalence of corticosteroid use than patients with late RNA clearance. However, corticosteroid use was not an independent risk factor for prolonged viral RNA shedding in the multivariable model [4]. Using least absolute shrinkage and selection operator analysis, Li et al [5] demonstrated that high-dose (80 mg/d) but not low-dose (40 mg/d) corticosteroids potentially delayed viral shedding in patients with COVID-19. Considering the potential influence of corticosteroid dosage on viral clearance, we conducted supplemental analysis on the previous data. Since COVID-19 is an emerging infectious disease, the treatment experience was lacking. During the course of treatment, different corticosteroid dosages were tried. Basically, the use of corticosteroids in these patients could be categorized into 2 types: glucocorticoid pulse therapy for 3 days (intravenous methylprednisolone: 200–400 mg/d) and low-to medium-dose corticosteroids for 21 days. The low-to medium-dose corticosteroid regimen included intravenous methylprednisolone 0.5–2 mg/kg body weight (bw) daily for 3 days, which was reduced to half for 3–5 days, then replaced with oral methylprednisolone (half of previous dosage) for 3–5 days. The dose is halved every 3 days until therapy is discontinued. The whole course of corticosteroids therapy lasts approximately 21 days. The influence of corticosteroid therapy and dose on viral shedding duration and treatment outcomes was evaluated in this study.

The data on 113 patients enrolled in our previous study were analyzed [4]. Among 113 patients, corticosteroids were used in 56.6% of patients (64 cases). The 64 patients were divided into 3 groups: 1 group with patients treated with lowdose corticosteroid (0.5–1 mg/kg bw daily), 1 group with patients treated with medium-dose corticosteroid (1–2 mg/kg bw daily), and another group with patients who received high-dose corticosteroid (glucocorticoid pulse therapy; intravenous methylprednisolone: 200–400 mg for 3 days). Clinical characteristics and treatment outcomes of these 3 groups and patients without corticosteroid use were summarized and compared. There were 4 groups: patients without corticosteroids (n= 49), those with lowdose corticosteroids (n= 21), those with medium-dose corticosteroids (n= 19), and those with high-dose corticosteroids (n= 24). A comparison of illness severity and treatment responses is shown in Table 1. The ratio of male patients and comorbidity with hypertension were comparable among the 4 groups. The high-dose-group patients were older than the patients in the other 3 groups (P=. 0004). The percentage of patients diagnosed as having severe/critical illness at admission was significantly higher in the medium-dose group than in the group …