title: Validity of diagnostic codes and liver-related laboratory abnormalities to identify hepatic decompensation events in the Veterans Aging Cohort Study.
abstract: OBJECTIVE
  The absence of validated methods to identify hepatic decompensation in cohort studies has prevented a full understanding of the natural history of chronic liver diseases and impact of medications on this outcome. We determined the ability of diagnostic codes and liver-related laboratory abnormalities to identify hepatic decompensation events within the Veterans Aging Cohort Study (VACS).
  
  
  METHODS
  Medical records of patients with hepatic decompensation codes and/or laboratory abnormalities of liver dysfunction (total bilirubin ≥ 5.0 g/dL, albumin ≤ 2.0 g/dL, INR ≥ 1.7) recorded 1 year before through 6 months after VACS entry were reviewed to identify decompensation events (i.e., ascites, spontaneous bacterial peritonitis, variceal hemorrhage, hepatic encephalopathy, hepatocellular carcinoma) at VACS enrollment. Positive predictive values (PPVs) of diagnostic codes, laboratory abnormalities, and their combinations for confirmed outcomes were determined.
  
  
  RESULTS
  Among 137 patients with a hepatic decompensation code and 197 with a laboratory abnormality, the diagnosis was confirmed in 57 (PPV, 42%; 95%CI, 33%-50%) and 56 (PPV, 28%; 95%CI, 22%-35%) patients, respectively. The combination of any code plus laboratory abnormality increased PPV (64%; 95%CI, 47%-79%). One inpatient or ≥2 outpatient diagnostic codes for ascites, spontaneous bacterial peritonitis, or variceal hemorrhage had high PPV (91%; 95%CI, 77%-98%) for confirmed hepatic decompensation events.
  
  
  CONCLUSIONS
  An algorithm of 1 inpatient or ≥ 2 outpatient codes for ascites, peritonitis, or variceal hemorrhage has sufficiently high PPV for hepatic decompensation to enable its use for epidemiologic research in VACS. This algorithm may be applicable to other cohorts.
authors.affiliation: Philadelphia VA Medical Center, Philadelphia, PA, USA; Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA. vincentl@mail.med.upenn.edu
authors.forename: Vincent
authors.initials: V
authors.lastname: Lo Re
authors.forename: Joseph K
authors.initials: JK
authors.lastname: Lim
authors.forename: Matthew Bidwell
authors.initials: MB
authors.lastname: Goetz
authors.forename: Janet
authors.initials: J
authors.lastname: Tate
authors.forename: Harini
authors.initials: H
authors.lastname: Bathulapalli
authors.forename: Marina B
authors.initials: MB
authors.lastname: Klein
authors.forename: David
authors.initials: D
authors.lastname: Rimland
authors.forename: Maria C
authors.initials: MC
authors.lastname: Rodriguez-Barradas
authors.forename: Adeel A
authors.initials: AA
authors.lastname: Butt
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Gibert
authors.forename: Sheldon T
authors.initials: ST
authors.lastname: Brown
authors.forename: Farah
authors.initials: F
authors.lastname: Kidwai
authors.forename: Cynthia
authors.initials: C
authors.lastname: Brandt
authors.forename: Zachariah
authors.initials: Z
authors.lastname: Dorey-Stein
authors.forename: K Rajender
authors.initials: KR
authors.lastname: Reddy
authors.forename: Amy C
authors.initials: AC
authors.lastname: Justice
mesh_terms: D000328:Adult; D000465:Algorithms; D002908:Chronic Disease; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D008103:Liver Cirrhosis / Q000150:complications / Q000175:diagnosis*; D008107:Liver Diseases / Q000175:diagnosis* / Q000503:physiopathology; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014481:United States; D014728:Veterans