Impact of socioeconomic status on mortality and unplanned readmission in septic intensive care unit patients

BACKGROUND: Little is known about the potential association between socioeconomic status (SES) and prognosis after sepsis. We analysed how SES impacted mortality and readmission in septic patients treated at the intensive care unit (ICU) of a university hospital. METHODS: We performed a cohort study including all adult patients admitted to a general tertiary ICU with severe sepsis or septic shock during 2008-2010. Data on SES (educational level, personal income, and cohabitation), comorbidity, readmissions, and mortality were obtained from public registries. We used Cox regression analysis to examine the impact of SES on 30- and 180-day mortality and on first unplanned readmission within 180 days after hospital discharge. RESULTS: A total of 387 patients were included of whom 111 (29%) died within 30 days after ICU admission, and 55 (20%) died within 180 days after hospital discharge. Adjusted for sex, comorbidity and SAPS II, patients with low income had a substantially greater risk of dying within 30 days of admission compared to those with high income (35.7% vs. 23.3%; adjusted hazard ratio (HR) 1.99; 95% confidence interval (CI) 1.24-3.21), and tended to show higher 180-day mortality (25.0% vs. 15.5%; adjusted HR 1.72; 95% CI 0.86-3.45). Among patients discharged from hospital, 125 (45%) were readmitted within 180 days. Patients with low education and low income showed a tendency towards early readmission. CONCLUSIONS: Among septic ICU patients, low income was significantly associated with increased 30-day mortality. There was a trend towards earlier readmission among surviving patients with low educational level and personal income.