Clinical characteristics associated with ARDS and mortality in patients with COVID-19 who received corticosteroid therapy

Background Corticosteroids are commonly used to manage severe Coronavirus disease 2019 (COVID-19) to prevent complications such as acute respiratory distress syndrome (ARDS) and mortality. However, their effectiveness varies. We assessed the clinical outcomes and risk factors associated with ARDS and mortality among patients with severe COVID-19 treated with corticosteroids. Methods We conducted a multi-center retrospective observational cohort study of 317 patients with severe COVID-19 who received corticosteroid therapy at hospitals in Quebec, Canada, from August 2020 to September 2022. Patient comparisons included: ARDS vs non-ARDS cases, survivors vs non-survivors, and survival profiles within ARDS/non-ARDS subgroups. Clinical characteristics, laboratory values, and outcomes were analyzed using chi-squared or Fisher's exact tests for categorical variables and t-tests or Mann-Whitney-Wilcoxon tests for continuous variables. Independent predictors of ARDS development and mortality were identified through multivariate logistic regression analysis. Results Logistic regression identified prior myocardial infarction as the only clinical comorbidity associated with ARDS development (OR = 3.64, 95% CI [1.11-11.94]). Notably, basophil counts showed a strong inverse relationship with ARDS development (OR = 5E-09, 95% CI [2.16E-15-0.012]). Age emerged as a significant predictor of mortality (OR = 1.07 per year, 95% CI [1.05-1.10]), along with previous lung disease (OR = 3.88, 95% CI [1.04-5.74]). Mortality was significantly higher in ARDS patients (40.6 % vs. 19.0 %, P < 0.0001). Surprisingly, obesity was associated with increased survival, particularly in ARDS patients (32.1 % vs. 9.6 %, P = 0.037). Conclusion The inverse relationship between basophil counts and ARDS development suggests a potential role for these cells in COVID-19 immune response. These findings reveal complex relationships between COVID-19, ARDS, and corticosteroids, generating new hypotheses for investigation.