title: The impact of chronic liver disease on the risk assessment of ACS NSQIP morbidity and mortality after hepatic resection.
abstract: BACKGROUND
  The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) risk-adjustment model for patients who require hepatic resection does not include metrics of underlying chronic liver disease. The applicability of the current risk adjustment model is under debate. This study aims to assess the impact of chronic liver disease on the ACS NSQIP estimates of postoperative morbidity and mortality.
  
  
  METHODS
  This retrospective cohort study included all cases of hepatic resection at our quaternary referral institution between 2006 and 2013. Metrics of chronic liver disease were abstracted and linked with the ACS NSQIP risk-adjustment model estimated probabilities of morbidity and mortality for each case. Sequential general linear models were used to estimate differences in ACS NSQIP probabilities of morbidity and mortality associated with measures of underlying chronic liver disease.
  
  
  RESULTS
  A total of 522 hepatic resections were performed during the study period. The patient cohort included 91 patients with fibrosis (17%) and 38 patients with cirrhosis (7%). The mean ACS NSQIP estimated probability of morbidity was 0.24 ± 0.11 and probability of mortality was 0.02 ± 0.02. Fibrosis was associated with increased probability of morbidity (0.26 ± 0.11; P = .019); cirrhosis was also associated with increased probability of morbidity (0.27 ± 0.10; P = .059). Parenchymal liver disease was not associated with increased probability of mortality (all P ≥ .62). Increased probabilities of mortality were associated with diagnosis and extent of resection (both P < .001).
  
  
  CONCLUSIONS
  In patients selected for hepatectomy, metrics of chronic liver disease were associated with differences in ACS NSQIP estimated probability of morbidity. Incorporation of metrics of chronic liver disease into the ACS NSQIP targeted hepatectomy modules should improve estimates of risk after hepatic resection.
authors.affiliation: Section of Hepatobiliary and Pancreatic Surgery, Department of Surgery, University of Virginia, Charlottesville, VA; Surgical Outcomes Research Center, University of Virginia, Charlottesville, VA. Electronic address: vz8h@virginia.edu.
authors.forename: Victor M
authors.initials: VM
authors.lastname: Zaydfudim
authors.affiliation: Section of Hepatobiliary and Pancreatic Surgery, Department of Surgery, University of Virginia, Charlottesville, VA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Kerwin
authors.affiliation: Surgical Outcomes Research Center, University of Virginia, Charlottesville, VA; Department of Surgery, University of Virginia, Charlottesville, VA.
authors.forename: Florence E
authors.initials: FE
authors.lastname: Turrentine
authors.affiliation: Section of Hepatobiliary and Pancreatic Surgery, Department of Surgery, University of Virginia, Charlottesville, VA.
authors.forename: Todd W
authors.initials: TW
authors.lastname: Bauer
authors.affiliation: Section of Hepatobiliary and Pancreatic Surgery, Department of Surgery, University of Virginia, Charlottesville, VA.
authors.forename: Reid B
authors.initials: RB
authors.lastname: Adams
authors.affiliation: Surgical Outcomes Research Center, University of Virginia, Charlottesville, VA; Division of Patient Outcomes, Policy & Population Research, University of Virginia, Charlottesville, VA.
authors.forename: George J
authors.initials: GJ
authors.lastname: Stukenborg
mesh_terms: D000328:Adult; D002908:Chronic Disease; D016208:Databases, Factual; D006498:Hepatectomy; D006801:Humans; D016014:Linear Models; D008107:Liver Diseases / Q000401:mortality / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies; D020379:Risk Adjustment; D018570:Risk Assessment; D012307:Risk Factors