The Effect of Hospital Volume on Mortality in Patients Admitted with Severe Sepsis

Importance The association between hospital volume and inpatient mortality for severe sepsis is unclear. Objective To assess the effect of severe sepsis case volume and inpatient mortality. Design Setting and Participants Retrospective cohort study from 646,988 patient discharges with severe sepsis from 3,487 hospitals in the Nationwide Inpatient Sample from 2002 to 2011. Exposures The exposure of interest was the mean yearly sepsis case volume per hospital divided into tertiles. Main Outcomes and Measures Inpatient mortality. Results Compared with the highest tertile of severe sepsis volume (>60 cases per year), the odds ratio for inpatient mortality among persons admitted to hospitals in the lowest tertile (≤10 severe sepsis cases per year) was 1.188 (95% CI: 1.074–1.315), while the odds ratio was 1.090 (95% CI: 1.031–1.152) for patients admitted to hospitals in the middle tertile. Similarly, improved survival was seen across the tertiles with an adjusted inpatient mortality incidence of 35.81 (95% CI: 33.64–38.03) for hospitals with the lowest volume of severe sepsis cases and a drop to 32.07 (95% CI: 31.51–32.64) for hospitals with the highest volume. Conclusions and Relevance We demonstrate an association between a higher severe sepsis case volume and decreased mortality. The need for a systems-based approach for improved outcomes may require a high volume of severely septic patients.