title: A Model to Predict the Severity of Acute Pancreatitis Based on Serum Level of Amylase and Body Mass Index.
abstract: OBJECTIVE
  Most patients with acute pancreatitis (AP) develop mild disease, but up to 20% develop severe disease. Many clinicians monitor serum levels of amylase and lipase in an attempt to predict the disease course, but this strategy has not been recommended by practice guidelines. We performed a retrospective analysis to determine whether the percentage changes in amylase and lipase were associated with the severity of disease that developed in patients with AP.
  
  
  METHODS
  We analyzed data collected from 182 consecutive patients with AP (21 with severe AP) admitted to the Cleveland Clinic from January 2008 through May 2010 (discover cohort). The association between 11 different factors and the severity of AP were assessed by univariable analysis; multivariable models were explored through stepwise selection regression. The percentage change in the serum level of amylase was calculated as follows: ([amylase day 1 - amylase day 2]/amylase day 1) × 100. The percentage change in amylase and body mass index (BMI) were combined to generate a z-score (z = -5.9 + [0.14 × BMI] + [0.01 × percentage change in amylase]), which was converted into a probability distribution called the change in amylase and BMI (CAB) score. The CAB score was validated using the AP database at the University of Pittsburgh Medical Center (140 patients, 35 with severe AP); we calculated p-scores for each patient and estimated the area under the receiver operating characteristics curve values.
  
  
  RESULTS
  Univariable analysis identified the percentage change in the serum level of amylase and other factors to be associated significantly with the severity of AP (P = .017). The CAB score was best at identifying patients who developed severe AP, with an area under the receiver operating characteristics curve value of 0.79 in the discovery cohort (95% confidence interval, 0.71-0.87) and 0.731 in the validation cohort (95% confidence interval, 0.61-0.84).
  
  
  CONCLUSIONS
  We developed a model to identify patients most likely to develop severe AP based on the percentage changes in serum level of amylase during the first 2 days after admission to the hospital and BMI.
authors.affiliation: Department of Gastroenterology and Hepatology, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Arthi
authors.initials: A
authors.lastname: Kumaravel
authors.affiliation: Department of Gastroenterology and Hepatology, Cleveland Clinic Foundation, Cleveland, Ohio. Electronic address: stevent@ccf.org.
authors.forename: Tyler
authors.initials: T
authors.lastname: Stevens
authors.affiliation: Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors.forename: Georgios I
authors.initials: GI
authors.lastname: Papachristou
authors.affiliation: Department of Gastroenterology and Hepatology, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Venkata
authors.initials: V
authors.lastname: Muddana
authors.affiliation: Department of Gastroenterology and Hepatology, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Amit
authors.initials: A
authors.lastname: Bhatt
authors.affiliation: Department of Gastroenterology and Hepatology, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Peter Junwoo
authors.initials: PJ
authors.lastname: Lee
authors.affiliation: Department of Gastroenterology and Hepatology, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Jordan
authors.initials: J
authors.lastname: Holmes
authors.affiliation: Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Rocio
authors.initials: R
authors.lastname: Lopez
authors.affiliation: Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors.forename: David C
authors.initials: DC
authors.lastname: Whitcomb
authors.affiliation: Department of Gastroenterology and Hepatology, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Mansour A
authors.initials: MA
authors.lastname: Parsi
mesh_terms: D000328:Adult; D000368:Aged; D000681:Amylases / Q000097:blood*; D015992:Body Mass Index; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019283:Pancreatitis, Acute Necrotizing / Q000175:diagnosis* / Q000473:pathology*; D012189:Retrospective Studies; D044967:Serum / Q000201:enzymology*; D012720:Severity of Illness Index
chemical_list: D000681:Amylases
keywords: Inflammation; Pancreas; Prognosis; Risk Factor; Scoring System