Age- and Sex-Related Outcomes in Patients with Sepsis or Septic Shock: A Prospective Monocentric Cohort Study

Background: Despite advances in the diagnosis and management of sepsis and septic shock (SS), sepsis is still characterized by mortality rates of up to 30% at 30 days, underlining the need for optimized risk stratification. This study investigated the influence of age and sex on short-term mortality in patients with sepsis and SS. Methods: This prospective, single-center, observational study included consecutive patients with sepsis/SS treated at a medical intensive care unit (ICU) of a University Medical Center between 2019 and 2021. Sepsis and SS were defined according to Sepsis-3 criteria. Patients were stratified by sex and age (≤75 vs. >75 years and per one-year increase). The primary endpoint was 30-day all-cause mortality. Survival was assessed by Kaplan-Meier and multivariable Cox regression analyses. Results: A total of 361 patients were included after screening 2596 ICU patients. Baseline characteristics were largely similar between men and women, whereas older patients had a greater burden of cardiovascular comorbidities and higher illness severity; 30-day mortality did not differ between men and women (51.9% vs. 52.3%; p = 0.948), whereas patients aged >75 years had higher 30-day mortality than younger patients (60.2% vs. 47.9%; p = 0.027). In multivariable Cox regression, age > 75 years remained independently associated with mortality (HR 1.391, 95% CI 1.021-1.896; p = 0.036), while sex was not (HR 1.016, 95% CI 0.740-1.396; p = 0.920). Sensitivity analysis using age as a continuous variable confirmed this association. Conclusions: In this prospective, registry-based, ICU cohort, older age was independently associated with higher short-term mortality in patients with sepsis or SS, whereas sex was not. Sex-related differences in treatment intensity and organ dysfunction markers were nevertheless observed and warrant further investigation.