Association between hospital case volume and mortality in pediatric sepsis: A retrospective observational study using a Japanese nationwide inpatient database

Introduction The survival benefits of treatment at high-volume hospitals (HVHs) are well-documented for several critical pediatric conditions. However, their impact on pediatric sepsis, a leading cause of mortality among children, remains understudied. Aim of the study To investigate the association between hospital case volume and mortality rates in pediatric sepsis. Material and Methods We conducted a retrospective cohort study using data from the Diagnosis Procedure Combination database. The study included patients who met the following criteria: 1) aged 28 days to 17 years; 2) discharged from the hospital between April 2014 and March 2018; 3) had a sepsis diagnosis coded under the International Classification of Diseases, 10th revision; 4) underwent blood cultures on hospital admission day (day 0) or day 1; 5) received antimicrobial agents on day 0 or 1; and 6) required at least one organ support measure (e.g., mechanical ventilation or vasopressors) on day 0 or 1. Hospitals were categorized by case volume during the study period, with HVHs defined as those in the highest quartile and low-volume hospitals (LVHs) as those in the remaining quartiles. In-hospital mortality rates between HVH and LVH groups were compared using mixed-effects logistic regression analysis with propensity score (PS) matching. Results A total of 934 pediatric patients were included in the study, with an overall in-hospital mortality rate of 16.1%. Of them, 234 were treated at 5 HVHs (>= 26 patients in 4 years), and 700 at 234 LVHs (<26 patients in 4 years). Upon PS matching, patients treated at HVHs demonstrated significantly lower odds of in-hospital mortality compared with those treated at LVHs (odds ratio, 0.42; 95% confidence interval, 0.22-0.80; P = 0.008). Conclusions In pediatric patients with sepsis, treatment at HVHs was associated with lower odds of in-hospital mortality.