The effect of comorbidity and age on hospital mortality and length of stay in patients with sepsis

Abstract

Purpose Sepsis is believed to be responsible for substantial health care burden, but there is limited information about its magnitude and the factors affecting health outcomes in Asian population. The aim of the study was to assess the disease burden of sepsis and to test the usefulness of Charlson Comorbidity Index (CCI) and age as risk-adjusted hospital mortality predictors in patients with sepsis using hospital administrative database. Methods A retrospective cohort study of hospital discharge database from 2004 to 2007 to identify cases with sepsis, comorbidity, and organ failure using the International Statistical Classification of Diseases and Related Health Problems, 9th Revision, Australian Modification codes was conducted. Results Of 305 637 hospitalized patients over 4 years, 6929 (2.27%) patients had sepsis, with 1216 (17.5%) patients associated with intensive care unit (ICU) admission. The mortality rates increased consistently in patients with CCI ranging from none to low, moderate and high grade for both patients with ICU admission (39.4%, 51.6%, 55.9%, and 54.3% respectively; P < .001) and patients without ICU admission (6.4%, 8.7%, 17.1%, and 25.3% respectively; P < .001). Logistic regression analysis showed that CCI (odds ratio, 11.8; high versus none) and age (odds ratio, 8.46; aged 85 years and older versus aged 18-54 years old) were significant and independent predictors of hospital mortality. Similar results were seen with hospital length of stay by zero-truncated negative binomial regression model analysis. Conclusion The sepsis-related mortality and resource utilization are high in this population as well. Comorbidities and advanced age were some of the most important contributors to hospital mortality and resource utilization.