title: Natural history of Crohn's disease in a population-based cohort from Cardiff (1986-2003): a study of changes in medical treatment and surgical resection rates.
abstract: BACKGROUND
  Benefits of immunosuppressive therapy in Crohn's disease have been demonstrated in controlled trials; however, it is unclear whether these drugs alter the longer-term natural history of this condition.
  
  
  OBJECTIVE
  To assess changes in disease outcomes in a population-based cohort of patients diagnosed in Cardiff from 1986 to 2003. Case notes from Crohn's disease incidence studies in Cardiff were reviewed retrospectively for disease characteristics and follow-up information on drug therapy, and the need for surgery for Crohn's disease. The study population was divided into three groups by year of diagnosis (Group A=1986-1991, Group B=1992-1997 and Group C=1998-2003).
  
  
  RESULTS
  341 patients were included. Kaplan-Meier (KM) analysis showed increasing use of immunosuppressants over time. At 5 years after diagnosis this was 11% in Group A, 28% in Group B, and 45% in Group C (p=0.001) and the median time to start of thiopurines was 77, 21 and 11 months in Group A, B and C respectively. There was a significant reduction in long-term steroid use at 5 years post diagnosis: 45 (44%), 31 (31%) and 24 (19%) patients in Group A, B and C respectively (p=0.001). KM analysis showed a significant reduction in the cumulative probability of intestinal surgery: At 5 years this was 59% (Group A), 37% (Group B) and 25% (Group C) (p=0.001). In a multivariate Cox analysis, year of diagnosis, disease location, oral corticosteroids within 3 months of diagnosis and early thiopurine use (within the first year of diagnosis) were all independent factors affecting likelihood of intestinal surgery.
  
  
  CONCLUSIONS
  This population-based cohort shows marked changes in rates of surgery, and the reduction is independently associated with year of diagnosis, and associated temporally with increased and earlier thiopurine use.
authors.affiliation: Department of Gastroenterology, University Hospital of Wales Cardiff, UK.
authors.forename: A V
authors.initials: AV
authors.lastname: Ramadas
authors.forename: S
authors.initials: S
authors.lastname: Gunesh
authors.forename: G A O
authors.initials: GA
authors.lastname: Thomas
authors.forename: G T
authors.initials: GT
authors.lastname: Williams
authors.forename: A B
authors.initials: AB
authors.lastname: Hawthorne
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001379:Azathioprine / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003424:Crohn Disease / Q000188:drug therapy* / Q000453:epidemiology / Q000601:surgery; D013505:Digestive System Surgical Procedures / Q000706:statistics & numerical data / Q000639:trends; D004334:Drug Administration Schedule; D004812:Epidemiologic Methods; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D015122:Mercaptopurine / Q000627:therapeutic use; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology / Q000209:etiology; D014852:Wales / Q000453:epidemiology; D055815:Young Adult
chemical_list: D005938:Glucocorticoids; D007166:Immunosuppressive Agents; D015122:Mercaptopurine; D001379:Azathioprine