Corticosteroid Therapy for Patients With Severe Fever With Thrombocytopenia Syndrome: A Nationwide Propensity Score–Matched Study in Japan

Severe fever with thrombocytopenia syndrome (SFTS) is a life-threatening infectious disease for which no effective treatment strategy has been established. Although corticosteroids (CSs) are widely administered to patients with SFTS, their efficacy remains uncertain. This study aimed to assess the impact of CS therapy on the in-hospital mortality of patients with SFTS.In this nationwide observational study using the Japanese Diagnosis Procedure Combination database, patients hospitalized for SFTS from April 2013 to March 2021 were reviewed. We compared patients who were treated with CSs to those who were treated without them after propensity score matching to adjust for their background, disease severity, and combination therapy.We included 494 patients with SFTS, and 144 pairs of them were analyzed after propensity score matching. No significant difference in the 30-day mortality (19% vs 15%, P = .272) and the number of survival days (log-rank test, P = .392) was found between the CS treatment group and the non-CS treatment group. However, in subgroup analyses, the CS treatment group tended to have better survival among patients with impaired consciousness on admission and/or shock status within 7 days after admission.CS therapy does not seem effective for all patients with SFTS; however, the impact might be altered by disease severity assessed by the consciousness level and shock status. A large-scale interventional study is required to determine its efficacy, especially for critically ill patients with SFTS.