Intermediate-term and long-term mortality among acute medical patients hospitalized with community-acquired sepsis: a population-based study

Abstract

Admission with severe sepsis is associated with an increased short-term mortality, but it is unestablished whether sepsis severity has an impact on intermediate-term and long-term mortality following admission to an acute medical admission unit. This was a population-based study of all adults admitted to an acute medical admission unit, Odense University Hospital, Denmark, from September 2010 to August 2011, identified by symptoms and clinical findings. We categorized the mortality periods into intermediate-term (31-180 days) and long-term (181-365, 366-730, and 731-1096 days). Mortality hazard ratios (HRs), comparing patients admitted with sepsis with those of a well-defined background population, were estimated using multivariable Cox regression. HRs were presented with 95% confidence intervals. In total, 621 (36.3%) presented with sepsis, 1071 (62.5%) presented with severe sepsis, and 21 (1.2%) presented with septic shock. Thirty-day all-cause mortality for patients with sepsis, severe sepsis, and septic shock was 6.1, 18.8, and 38.1%, respectively. The adjusted HR among patients with sepsis of any severity within the time periods 31-180, 181-365, 366-720, and 721-1096 days was 7.1 (6.0-8.5), 2.8 (2.3-3.5), 2.1 (1.8-2.6), and 2.2 (1.7-2.9), respectively. Long-term mortality was unrelated to sepsis severity [721-1096 days: sepsis HR: 2.2 (1.5-3.2), severe sepsis HR: 2.1 (1.5-3.0)]. Patients admitted with community-acquired sepsis showed high intermediate-term mortality, increasing with sepsis severity. Long-term mortality was increased two-fold compared with sepsis-free individuals, but might be explained by unmeasured confounding. Further, long-term mortality was unrelated to sepsis severity.