Association Between Hospital Case Volume of Sepsis, Adherence to Evidence-Based Processes of Care and Patient Outcomes.

OBJECTIVES: We sought to explore potential mechanisms underlying hospital sepsis case volume-mortality associations by investigating implementation of evidence-based processes of care.

DESIGN: Retrospective cohort study. We determined associations of sepsis case volume with three evidence-based processes of care (lactate measurement during first hospital day, norepinephrine as first vasopressor, and avoidance of starch-based colloids) and assessed their role in mediation of case volume-mortality associations.

SETTING: Enhanced administrative data (Premier, Charlotte, NC) from 534 U.S. hospitals.

SUBJECTS: A total of 287,914 adult patients with sepsis present at admission between July 2010 and December 2012 of whom 58,045 received a vasopressor for septic shock during the first 2 days of hospitalization.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Among patients with sepsis, 1.9% received starch, and among patients with septic shock, 68.3% had lactate measured and 64% received norepinephrine as initial vasopressor. Patients at hospitals with the highest case volume were more likely to have lactate measured (adjusted odds ratio quartile 4 vs quartile 1, 2.8; 95% CI, 2.1-3.7) and receive norepinephrine as initial vasopressor (adjusted odds ratio quartile 4 vs quartile 1, 2.1; 95% CI, 1.6-2.7). Case volume was not associated with avoidance of starch products (adjusted odds ratio quartile 4 vs quartile 1, 0.73; 95% CI, 0.45-1.2). Adherence to evidence-based care was associated with lower hospital mortality (adjusted odds ratio, 0.81; 95% CI, 0.70-0.94) but did not strongly mediate case volume-mortality associations (point estimate change ≤ 2%).

CONCLUSIONS: In a large cohort of U.S. patients with sepsis, select evidence-based processes of care were more likely implemented at high-volume hospitals but did not strongly mediate case volume-mortality associations. Considering processes and case volume when regionalizing sepsis care may maximize patient outcomes.