Socioeconomic disadvantage and sepsis survival in Australian intensive care units: A retrospective cohort study

OBJECTIVE: The aim of this study was to investigate the association between socioeconomic status (SES) and sepsis survival in Australian intensive care unit (ICU) admissions. METHODS: We conducted a retrospective cohort study of adult sepsis ICU admissions between 2018 and 2023, using ICU registry and national death data. SES was derived using the Australian Bureau of Statistics Index of Relative Socioeconomic Advantage and Disadvantage deciles mapped from residential postcodes and categorised as low, middle, or high. Unadjusted survival to 180 days and in-hospital 30-day survival were described using Kaplan-Meier estimates. Cox proportional hazard models, adjusted for age, sex, organ failure, ICU admission source, elective surgical status, chronic conditions, admission year, study site, and the presence of septic shock, were used to determine associations between SES and survival. RESULTS: Of 794,756 admissions, 80,422 (10.1%) were sepsis admissions; 180-day mortality was 7570 of 31,528 (24·0%) in low SES admissions compared to 5109 of 22262 (22.9%) and 6009 of 26,088 (23·0%) in middle and high SES admissions, respectively. In-hospital 30-day mortality was 4662 of 31,613 (14·7%) in low SES admissions compared to 3079 of 22348 (13.7%) and 3695 of 26,221 (14·1%) in middle and high SES admissions, respectively. In adjusted Cox regression models, high SES was associated with greater 180-day and in-hospital 30-day survival (adjusted hazard ratio: 0·86, 95% confidence interval: 0·83-0·90; p < 0·001 and adjusted hazard ratio: 0·88, 95% confidence interval: 0·84-0·93; p < 0·001, respectively). CONCLUSION: People living in areas of socioeconomic disadvantage had lower survival to day 180 after an ICU admission for sepsis than people living in other areas.