title: Evolution of clinical behaviour in Crohn's disease: predictive factors of penetrating complications.
abstract: OBJECTIVE
  Crohn's disease is a heterogeneous entity. The Vienna Classification defines three different clinical patterns: 'non-stricturing, non-penetrating', 'stricturing' and 'penetrating'. Aim of this study was to assess the change in clinical behaviour over time and to evaluate whether an evolution towards penetrating complications can be predicted.
  
  
  METHODS
  A total of 139 patients with non-penetrating behaviour at the time of diagnosis were included. The mean follow-up was 4.84 years (range 1-23.2 years). The clinical behaviour, according to the Vienna Criteria, was assessed at the diagnosis and at the end of follow up. Statistical analysis was performed by means of the Kaplan-Meier method and standard logistic regression analysis.
  
  
  RESULTS
  The cumulative probability of a change in clinical behaviour was 22, 38 and 63% at 3, 6 and 12 years, respectively, and the cumulative probability of developing penetrating complications was 22, 33 and 55% at 3, 6 and 12 years, respectively. Young age at diagnosis (<40 years) and a stricturing behaviour are independent risk factors of developing major penetrating complications (internal fistula, mass or abscess): OR=6.0, 95% CI 1.1-30.5; OR=4.0, 95% CI 1.5-10.9, respectively, but not perianal disease.
  
  
  CONCLUSIONS
  The behavioural classification of Crohn's disease is a dynamic model in which each status should be considered as not fixed but evolutive. Perianal disease should be considered a distinct pattern of penetrating behaviour.
authors.affiliation: Gastroenterology Unit, S. Filippo Neri Hospital, Via Martinotti 20, 00135 Rome, Italy. c.papi@fastwebnet.it
authors.forename: C
authors.initials: C
authors.lastname: Papi
authors.forename: V
authors.initials: V
authors.lastname: Festa
authors.forename: C
authors.initials: C
authors.lastname: Fagnani
authors.forename: A
authors.initials: A
authors.lastname: Stazi
authors.forename: G
authors.initials: G
authors.lastname: Antonelli
authors.forename: A
authors.initials: A
authors.lastname: Moretti
authors.forename: M
authors.initials: M
authors.lastname: Koch
authors.forename: L
authors.initials: L
authors.lastname: Capurso
mesh_terms: D000328:Adult; D000367:Age Factors; D003424:Crohn Disease / Q000150:complications / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D011379:Prognosis; D012307:Risk Factors; D012907:Smoking; D016019:Survival Analysis; D013997:Time Factors