Death and ICU Admission Associated with Sars-Cov-2 Variants in Immunocompromised Hospitalised Individuals: A National Observational Study.

Abstract

Introduction: Individuals who are immunocompromised (IC) with COVID-19 have consistently been associated with worse clinical outcomes than individuals who are non-immunocompromised (non-IC). The aim of this study was to describe and compare in-hospital outcomes between individuals who are IC and non-IC hospitalised with COVID-19, with a particular focus on mortality across periods defined by the predominant circulating SARS-CoV-2 variants.

Methods: This is an observational, retrospective, descriptive study based on a secondary database from Brazil's Unified Health System. Patients hospitalised with laboratory-confirmed COVID-19 were included. Descriptive statistics were used to summarize the cohort; categorical variables were expressed as frequencies and percentages, and continuous variables as mean ± standard deviation. Univariate logistic regression analyses were conducted to estimate the association between immunocompromised status and two key outcomes: in-hospital mortality and ICU admission, stratified by dominant SARS-CoV-2 variant. Results were reported as odds ratios (OR) with 95% confidence intervals (CI).

Results: Between March 2020 and July 2023, 361,898 hospitalised COVID-19 individuals were identified, with 2.07% (n = 7484) classified as IC. Those individuals consistently exhibited higher odds of death and ICU admission across all SARS-CoV-2 variant periods. The odds of in-hospital mortality ranged from OR: 1.20 (95% CI 1.04-1.39) during the original (WT) variant to OR: 2.39 (95% CI 1.54-3.71) during the Omicron XBB subvariant period; however, the absolute number of cases and deaths for XBB was small, and this OR might have limited clinical significance. The second highest risk for mortality was observed during the Delta wave (OR: 2.16; 95% CI 1.94-2.41), with a much greater number of cases and clinical significance.

Conclusion: Immunocompromised status was independently associated with higher odds of adverse hospital outcomes, including ICU admission and in-hospital mortality, regardless of the circulating SARS-CoV-2 variant.