Epidemiology and outcomes of adult (non-maternity) community-onset sepsis in Ireland: a secondary analysis of acute hospital administrative data 2020–2024

Background Community-onset sepsis accounts for most sepsis episodes, yet national-level data describing its epidemiology and outcomes remain limited in Ireland. Improved characterisation is needed to support prevention, early recognition, and service planning. Objectives To examine the epidemiology, infection sources, comorbidity burden, and outcomes of adult (non-maternity) community-onset sepsis in Irish hospitals. Methods We conducted a secondary analysis of Hospital In-Patient Enquiry data from all acute public hospitals in Ireland from January 2020 to December 2024. Sepsis admissions were identified using ICD-10-AM diagnostic codes. Demographic characteristics, comorbidity burden, infection source, critical care utilisation, and in-hospital mortality were analysed. Multivariable logistic regression was used to identify independent predictors of critical care admission and mortality. Results Among 68,644 sepsis episodes, 49,268 (71.7%) were community-onset. Of these, 92.6% ( n = 45,641) were adult (non-maternity). In-hospital mortality among community-onset was 19.2%. Mortality increased significantly with age, with episodes of individuals aged ≥ 95 years having the highest odds of death (adjOR 9.17, 95% CI 7.31–11.52) compared to those aged 25–44 years. Increasing multimorbidity was independently associated with mortality; three or more comorbidities were associated with over threefold higher odds of death (adjOR 3.24, 95% CI 2.98–3.52). Respiratory infections (adjOR 2.05) were associated with increased mortality, while urinary sources were associated with lower mortality (adjOR 0.50). Conclusions Community-acquired sepsis represents 72% of sepsis episodes in Ireland, predominantly affects older adults with multimorbidity. Prioritising prevention, early recognition, and timely management in the community including vaccination and prompt antibiotic treatment is essential to lowering morbidity and mortality.