Clinical Characteristics and Outcomes of Community-Onset and Hospital-Onset Sepsis Patients: The Korean Nationwide Sepsis Cohort Study

Background: Sepsis is a major global health concern with high morbidity and mortality.To address this burden in Korea, the Korean Sepsis Alliance established a nationwide registry to characterize community-onset and hospital-onset sepsis, to identify risk factors for mortality, and to assess the association between sepsis bundle compliance and mortality.Methods: We conducted a multicenter, prospective cohort study including adult patients with sepsis or septic shock enrolled in the Korean Sepsis Alliance registry from September 2019 to December 2023.A total of 17,246 patients from 15 geographically diverse tertiary or university-affiliated hospitals were included.Sepsis was defined according to the Sepsis-3 criteria.Clinical characteristics, infection sites, microbiological profiles, compliance with sepsis bundles, and outcomes were compared between patients with community-onset sepsis and hospital-onset sepsis.Multivariable Cox regression analysis was performed to identify factors independently associated with 28-day mortality.Results: Among the 17,246 enrolled patients, 14,600 (84.7%) had community-onset sepsis and 2,646 (15.3%) had hospital-onset sepsis.The incidence of sepsis in the whole cohort was 322.80 per 100,000, including 722.21 per 100,000 for community-onset sepsis and 79.68 per 100,000 for hospital-onset sepsis.Overall hospital mortality was 29.9%, with a higher rate observed in hospital-onset sepsis (36.9%) than in community-onset sepsis (28.7%, P < 0.001).Patients with hospital-onset sepsis had multiple comorbidities, greater sepsis severity, and infections caused by multi-drug-resistant organisms.Pulmonary infections were the most frequent source in both groups.Independent risk factors for 28-day mortality included hospital-onset sepsis, advanced age, poor performance status, comorbidities, septic shock, bloodstream infection, higher Sequential Organ Failure Assessment scores, and respiratory or systemic infections without an identifiable source.Compliance of the 1-, 3-, and 6-hour sepsis bundles was significantly associated with reduced 28-day mortality in both groups.Conclusion: This study presents the first nationwide data on the epidemiology of community-onset and hospital-onset sepsis in Korea.Compliance with time-based sepsis bundles was associated with lower mortality.These findings underscore the need for