title: Volume-Mortality Relationships during Hospitalization with Severe Sepsis Exist Only at Low Case Volumes.
abstract: BACKGROUND
  Volume-outcome associations have been demonstrated in conditions with high morbidity and mortality; however, the existing literature regarding such associations in sepsis is not definitive.
  
  
  OBJECTIVE
  To test the hypothesis that annual hospital severe sepsis case volume is associated with mortality during admissions with severe sepsis in teaching and nonteaching hospitals.
  
  
  METHODS
  This work was a retrospective cohort study of administrative data from the South Carolina State Inpatient Database using multivariate logistic regression and case mix adjustment.
  
  
  RESULTS
  In the calendar year 2010, 9,815 patients were admitted with severe sepsis or septic shock. Hospitals were stratified into low- (0-75 cases/yr, n = 26), intermediate- (76-300 cases/yr, n = 19), and high (>300 cases/yr, n = 12) -volume tertiles. Patients admitted to hospitals with a low annual case volume for sepsis had higher adjusted odds of dying before discharge (odds ratio, 1.56; 95% confidence interval, 1.25-1.94) compared with patients admitted to high-volume hospitals. Hospitalization at intermediate-volume hospitals was not associated with a difference in mortality (odds ratio, 0.99; 95% confidence interval, 0.90-1.09) compared with high-volume hospitals. There was no difference between the mortality rates of intermediate- and high-volume hospitals at different severity of illness quartiles. Hospital length of stay differed significantly by hospital case volume (low = 8.0, intermediate = 12.7, high = 14.9 [d]; P < 0.0001).
  
  
  CONCLUSIONS
  Hospitals with low annual sepsis case volume are associated with higher mortality rates, whereas hospitals with intermediate sepsis case volumes are associated with similar mortality rates compared with hospitals with high case volumes.
authors.affiliation: 1 Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, and.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Goodwin
authors.affiliation: 2 Department of Healthcare Leadership and Management, College of Health Professions, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Kit N
authors.initials: KN
authors.lastname: Simpson
authors.affiliation: 1 Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, and.
authors.forename: Dee W
authors.initials: DW
authors.lastname: Ford
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual; D005260:Female; D017052:Hospital Mortality; D061847:Hospitals, High-Volume / Q000706:statistics & numerical data*; D061846:Hospitals, Low-Volume / Q000706:statistics & numerical data*; D006801:Humans; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D012189:Retrospective Studies; D020379:Risk Adjustment / Q000592:standards*; D018805:Sepsis / Q000401:mortality*; D012720:Severity of Illness Index; D013022:South Carolina
keywords: critical illness; high volume; low volume; risk adjustment; sepsis