Addition of Baricitinib to COVID-19 Treatment Does Not Increase Bacterial Infection Compared to Standard Therapy: A Single-center Retrospective Study.

Objective The coronavirus disease 2019 (COVID-19) pandemic continues to spread across the world, and the utility of many drugs for treatment has been suggested. However, few studies have examined the efficacy and safety of treatment with baricitinib, remdesivir, and dexamethasone. Methods A retrospective, cohort study of patients who were admitted to Kurashiki Central Hospital in Japan between April 6 and June 29, 2021, was conducted. Differences in patients' background characteristics, clinical outcomes, and safety were investigated in the groups with and without baricitinib treatment. The primary outcome was the bacterial infection rate, and the secondary outcome was the 28-day mortality rate. An inverse probability of treatment weighting (IPTW) analysis, including 12 covariates, was used as a propensity score analysis to reduce biases. Results In total, there were 96 patients, including 43 in the baricitinib-containing therapy (BCT) group and 53 in the non-baricitinib-containing therapy (non-BCT) group. In the BCT group, the ordinal scale on admission was 2.3% with 4, 51.1% with 5, 23.3% with 6, and 23.3% with 7. In the non-BCT group, the ordinal scale was 1.9% with 3, 18.9% with 4, 58.5% with 5, 13.2% with 6, and 7.5% with 7. After adjusting by the IPTW analysis, the BCT group did not have an increased bacterial infection rate [odds ratio (OR), 1.1; 95% confidence interval (CI), 0.36-3.38; p=0.87] or 28-day mortality rate (OR, 0.31; 95% CI, 0.07-1.3; p=0.11) compared with the non-BCT group. Conclusion BCT can be administered without increasing the infection risk compared with non-BCT.