Hospital-onset sepsis and community-onset sepsis in critical care units in Japan: a retrospective cohort study based on a Japanese administrative claims database

Background Hospital- and community-onset sepsis are significant sepsis subgroups. Japanese data comparing these subgroups are limited. This study aimed to describe the epidemiology of hospital- and community-onset sepsis in critical care units in Japan. Methods We performed a retrospective cohort study using the Japanese Diagnosis and Procedure Combination database. Adult patients admitted to critical care units with sepsis from April 2010 to March 2020 were included. Sepsis cases were identified based on ICD-10 codes for infectious diseases, procedure codes for blood culture tests, and medication codes for antimicrobials. Patients' characteristics, in-hospital mortality, and resource utilization were assessed. The in-hospital mortality between groups was compared using the Poisson regression generalized linear mixed-effect model. Results Of 516,124 patients, 52,183 (10.1%) had hospital-onset sepsis and 463,940 (89.9%) had community-onset sepsis. Hospital-onset sepsis was characterized by younger age, infrequent emergency hospitalization, frequent surgery under general anesthesia, and frequent organ support upon critical care unit admission compared to community-onset sepsis. In-hospital mortality was higher for hospital-onset than for community-onset sepsis (35.5% versus 19.2%; unadjusted mean difference, 16.3% [95% confidence interval (CI) 15.9-16.7]; adjusted mean difference, 15.6% [95% CI 14.9-16.2]). Mean hospital length of stay was longer for hospital-onset than for community-onset sepsis (47 days versus 30 days; unadjusted mean difference, 17 days [95% CI 16-17]; adjusted mean difference, 13 days [95% CI 12-14]). Conclusion Patients with hospital-onset sepsis admitted to critical care units in Japan had a poorer prognosis and more resource utilization including organ support rate, number of days with critical care unit surcharge codes, and hospital length of stay than those with community-onset sepsis.