title: Use of a predictive equation for diagnosis of acute gangrenous cholecystitis.
abstract: BACKGROUND
  Factors previously identified by multivariate logistic regression that were predictive for gangrenous cholecystitis (GC) were used to develop a predictive equation. Our objective was to evaluate the sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values of this equation for detecting GC in patients with acute cholecystitis (AC).
  
  
  METHODS
  Medical records of patients who presented to a tertiary care hospital with AC were reviewed. Twenty-one patient and clinical variables were recorded. We prospectively tested the results of the following equation against pathologic diagnosis: P=e((0.7116+0.9944.DM+1.7157.WBC-1.0319.ALT.2.0518.ALP+2.7078.PCF))/(1+e([-0.7116+0.9944.DM+1.7157.WBC-1.0319.ALT-2.0518.ALP+2.7078.PCF])), where P = predicted value; DM = diabetes mellitus; WBC = white blood cell count; ALT = alanine aminotransferase; AST = aspartate aminotransferase; and PCF = pericholecystic fluid.
  
  
  RESULTS
  Ninety-eight patients presented with AC and 18% had GC (18 of 98). Using a cutoff of P = 0.724, our equation had a specificity of 93%, sensitivity of 83%, PPV of 71%, and NPV of 96%, P <0.001 for the detection of GC.
  
  
  CONCLUSIONS
  Our study demonstrates the equation may be useful in detecting the subset of AC patients who have GC.
authors.affiliation: Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Michael E. DeBakey VAMC, Houston Veterans Affairs Medical Center, OCL (112), 2002 Holcombe Blvd., Houston, TX 77030, USA.
authors.forename: Liz
authors.initials: L
authors.lastname: Nguyen
authors.forename: Shawn P
authors.initials: SP
authors.lastname: Fagan
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Lee
authors.forename: Nori
authors.initials: N
authors.lastname: Aoki
authors.forename: Kamal M F
authors.initials: KM
authors.lastname: Itani
authors.forename: David H
authors.initials: DH
authors.lastname: Berger
authors.forename: Samir S
authors.initials: SS
authors.lastname: Awad
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002763:Cholecystectomy / Q000379:methods; D041881:Cholecystitis, Acute / Q000175:diagnosis* / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D005734:Gangrene / Q000175:diagnosis* / Q000601:surgery*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods*; D011336:Probability; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016896:Treatment Outcome