Hospital Deaths in Patients With Sepsis From 2 Independent Cohorts

TLDR

Sepsis, the inflammatory response to infection, affects millions worldwide and the KPNC cohort, while similar to the broader Northern California population, has higher income and education levels. The study quantified sepsis’s contribution to hospital mortality using two complementary inpatient cohorts from Kaiser Permanente Northern California and the Nationwide Inpatient Sample. Data were drawn from the KPNC cohort of 482,828 adults (2010‑2012) and the NIS national sample of 6.5 million hospitalizations (2010), with sepsis identified via explicit ICD‑9 codes and an implicit Angus consensus approach, and most cases linked to quality‑improvement data.

Abstract

Hospital Deaths in Patients With Sepsis From 2 Independent CohortsSepsis, the inflammatory response to infection, affects millions of patients worldwide. 1However, its effect on overall hospital mortality has not been measured.We quantified the contribution of sepsis to mortality in 2 complementary inpatient cohorts from Kaiser Permanente Northern California (KPNC) and the Healthcare Cost and Utilization Project Nationwide Inpatient Sample (NIS).Methods | The KPNC cohort included 482 828 adults (aged ≥18 years) with overnight, nonobstetrical hospitalizations at 21 KPNC hospitals between 2010 and 2012. 2 Compared with all Northern California patients, KPNC patients have broadly similar health characteristics but higher income and educational attainment. 3The NIS, a nationally representative sample of 1051 hospitals, included 6.5 million unweighted adult hospitalizations in 2010. 4e used 2 approaches to identify patients with sepsis from International Statistical Classification of Diseases, Ninth Revision, Clinical Modification codes.The explicit approach identified those with codes 038 (septicemia), 995.91 (sepsis), 995.92 (severe sepsis), or 785.52 (septic shock).Because of the known underrecognition of sepsis, we also used an implicit approach adding patients with evidence of both infection and acute organ failure using the Angus implementation 5 of sepsis consensus criteria.Within KPNC data, we delineated diagnoses when coded as present on admission, an important consideration for improving identification and treatment efforts.Furthermore, we linked 97.9% (n = 19 621) of all explicit sepsis cases present on admission in 2012 to KPNC quality improvement data, permitting stratification of patients by com-