title: An index with improved diagnostic accuracy for the diagnosis of Crohn's disease derived from the Lennard-Jones criteria.
abstract: The Lennard-Jones criteria are considered the gold standard for diagnosing Crohn's disease (CD) and include the items granuloma, macroscopic discontinuity, transmural inflammation, fibrosis, lymphoid aggregates and discontinuous inflammation on histology. The criteria have never been subjected to a formal validation process.
  
  
  
  To develop a validated and improved diagnostic index based on the items of Lennard-Jones criteria.
  
  
  
  Included were 328 adult patients with long-standing CD (median disease duration 10 years) from three centres and classified as 'established', 'probable' or 'non-CD' by Lennard-Jones criteria at time of diagnosis. Controls were patients with ulcerative colitis (n = 170). The performance of each of the six diagnostic items of Lennard-Jones criteria was modelled by logistic regression and a new index based on stepwise backward selection and cut-offs was developed. The diagnostic value of the new index was analysed by comparing sensitivity, specificity and accuracy vs. Lennard-Jones criteria.
  
  
  
  By Lennard-Jones criteria 49% (n = 162) of CD patients would have been diagnosed as 'non-CD' at time of diagnosis (sensitivity/specificity/accuracy, 'established' CD: 0.34/0.99/0.67; 'probable' CD: 0.51/0.95/0.73). A new index was derived from granuloma, fibrosis, transmural inflammation and macroscopic discontinuity, but excluded lymphoid aggregates and discontinuous inflammation on histology. Our index provided improved diagnostic accuracy for 'established' and 'probable' CD (sensitivity/specificity/accuracy, 'established' CD: 0.45/1/0.72; 'probable' CD: 0.8/0.85/0.82), including the subgroup isolated colonic CD ('probable' CD, new index: 0.73/0.85/0.79; Lennard-Jones criteria: 0.43/0.95/0.69).
  
  
  
  We developed an index based on items of Lennard-Jones criteria providing improved diagnostic accuracy for the differential diagnosis between CD and UC.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Reinisch
authors.affiliation: Department of Internal Medicine IV, Wilhelminenspital, Vienna, Austria.
authors.forename: K
authors.initials: K
authors.lastname: Schweiger
authors.affiliation: Section for Medical Statistics, CeMSIIS, Medical University of Vienna, Vienna, Austria.
authors.forename: E
authors.initials: E
authors.lastname: Pablik
authors.affiliation: Inserm U954 and Department of Gastroenterology, Nancy University Hospital, Lorraine University, Vandoeuvre-les-Nancy, France.
authors.forename: B
authors.initials: B
authors.lastname: Collet-Fenetrier
authors.affiliation: Inserm U954 and Department of Gastroenterology, Nancy University Hospital, Lorraine University, Vandoeuvre-les-Nancy, France.
authors.forename: L
authors.initials: L
authors.lastname: Peyrin-Biroulet
authors.affiliation: Gastroenterology Department, IDIBAPS, CIBEREHD, Hospital Clinic Barcelona, Barcelona, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Alfaro
authors.affiliation: Gastroenterology Department, IDIBAPS, CIBEREHD, Hospital Clinic Barcelona, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Panés
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, McMaster University, Hamilton, ON, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Moayyedi
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.|Division of Gastroenterology, Department of Internal Medicine, McMaster University, Hamilton, ON, Canada.
authors.forename: W
authors.initials: W
authors.lastname: Reinisch
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003093:Colitis, Ulcerative / Q000175:diagnosis; D003424:Crohn Disease / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D055815:Young Adult