title: Risk models for post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP): smoking and chronic liver disease are predictors of protection against PEP.
abstract: OBJECTIVE
  We investigated which variables independently associated with protection against or development of postendoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) and severity of PEP. Subsequently, we derived predictive risk models for PEP.
  
  
  METHODS
  In a case-control design, 6505 patients had 8264 ERCPs, 211 patients had PEP, and 22 patients had severe PEP. We randomly selected 348 non-PEP controls. We examined 7 established- and 9 investigational variables.
  
  
  RESULTS
  In univariate analysis, 7 variables predicted PEP: younger age, female sex, suspected sphincter of Oddi dysfunction (SOD), pancreatic sphincterotomy, moderate-difficult cannulation (MDC), pancreatic stent placement, and lower Charlson score. Protective variables were current smoking, former drinking, diabetes, and chronic liver disease (CLD, biliary/transplant complications). Multivariate analysis identified seven independent variables for PEP, three protective (current smoking, CLD-biliary, CLD-transplant/hepatectomy complications) and 4 predictive (younger age, suspected SOD, pancreatic sphincterotomy, MDC). Pre- and post-ERCP risk models of 7 variables have a C-statistic of 0.74. Removing age (seventh variable) did not significantly affect the predictive value (C-statistic of 0.73) and reduced model complexity. Severity of PEP did not associate with any variables by multivariate analysis.
  
  
  CONCLUSIONS
  By using the newly identified protective variables with 3 predictive variables, we derived 2 risk models with a higher predictive value for PEP compared to prior studies.
authors.affiliation: Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA. mdimagno@umich.edu
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: DiMagno
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Spaete
authors.forename: Darren D
authors.initials: DD
authors.lastname: Ballard
authors.forename: Erik-Jan
authors.initials: EJ
authors.lastname: Wamsteker
authors.forename: Sameer D
authors.initials: SD
authors.lastname: Saini
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000379:methods*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008107:Liver Diseases / Q000150:complications*; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D015999:Multivariate Analysis; D010195:Pancreatitis / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*