The effect of baricitinib and corticosteroid compared to that of corticosteroid monotherapy in severely and critically ill patients with COVID-19: A Japanese multicenter inpatient database study.

Background: Systemic baricitinib and corticosteroids play important roles in treating severely and critically ill patients with coronavirus disease 2019 (COVID-19). However, the efficacy of the combination of baricitinib and corticosteroids compared to that of corticosteroid monotherapy in severely and critically ill hospitalized patients with COVID-19 remains unclear.

Methods: We analyzed severely and critically ill hospitalized patients with COVID-19 aged >18 years between January 1, 2020 and May 31, 2023, using a Japanese multicenter inpatient database. We performed propensity score matching to analyze the effect of the combination of baricitinib and corticosteroids within 2 days of hospital admission (combination group) on the 28-day and in-hospital mortality rates compared with those of corticosteroid monotherapy within 2 days of hospital admission (control group). Sensitivity analysis was performed using inverse probability weighting analysis and the generalized estimating equation method.

Results: The eligible patients (n = 7433) were divided into a combination (n = 679) and a control group (n = 6754). One-to-four propensity score matching analyses included 566 combination and 2264 control group patients. There was no significant difference in 28-day (8.5 % vs. 8.8 %; risk difference, -0.3 % [95 % confidence interval, -2.9 to 2.3]) or in-hospital (11 % vs. 10 %; risk difference, 1.0 [-1.9 to 3.9]) mortality rates between 2 groups. The sensitivity analysis showed similar outcomes.

Conclusion: This observational study, using a Japanese multicenter inpatient database, found that the combination of baricitinib and corticosteroid therapy did not improve the 28-day or in-hospital mortality rates in severely and critically ill patients with COVID-19 compared to corticosteroid monotherapy.