Age-related incidence and outcomes of sepsis in California, 2008-2015

Purpose: Sepsis remains amongst the most common causes of death worldwide. It has been described as a disease of the elderly, but contemporary data on risk factors and mortality is lacking.

Materials and methods: Multi-center longitudinal cohort study using non-public, state of California data from January 1, 2008 to September 31, 2015. Patients with sepsis, severe sepsis, and septic shock were identified using ICD-9-CM diagnosis and procedure codes with age subgroups of 18-44, 45-64, 65-74, 75-84, and >85 years old. Descriptive statistics and a single direct logistic regression model were used to present data on incidence and mortality and to identify independent factors associated with mortality.

Results: Of 30,282,159 total inpatient encounters, 20,358,569 met inclusion criteria and 1,566,306 met sepsis criteria. Conditions associated with mortality included metastatic cancer, age, liver disease, residing in a care facility, and a gastrointestinal source of infection as well as fungal infection. Mortality in the >85-year-old subgroup with septic shock was 45.7%, lower than previously reported.

Conclusion: Age remains an important sepsis risk factor, but other conditions correlated more closely with sepsis-associated death. Patients over 85 years of age suffering from septic shock may have a better chance of survival than previously thought.