Impact of hospital volume on mortality and cost in sepsis based on a Japanese nationwide medical claims database study

Abstract

Abstract We aimed to investigate the impact of hospital volume on the mortality rate and medical costs in sepsis. This retrospective study used the administrative data from 2010 to 2017. The hospital volume categorization into quartiles was performed according to the annual number of sepsis cases. The primary and secondary outcome was in-hospital mortality and medical costs, respectively. A mixed-effects logistic model with a two-level hierarchical structure was used to adjust for baseline imbalances. Among 1,781,014 sepsis patients from 1,622 hospitals, the crude in-hospital mortality rate was 22.1% and 17.0% in the lowest and highest quartile of sepsis volume, respectively (p < 0.0001). After adjustment for confounding factors, the in-hospital mortality in the highest quartile was significantly lower than that of the lowest quartile (odds ratio, 0.789; 95% confidence interval, 0.774–0.804). Investigations with fractional polynomials and restricted cubic splines revealed that the hospital volume was significantly associated with in-hospital mortality (p < 0.0001). The highest quartile had higher daily medical costs per person than those of the lowest quartile. In conclusion, this nationwide sepsis study using the medical claims database suggested that a higher hospital volume leads to lower in-hospital mortality and higher daily medical costs per person.