title: The changing face of Crohn's disease: a population-based study of the natural history of Crohn's disease in Örebro, Sweden 1963-2005.
abstract: OBJECTIVE
  Changes in medical therapy and surgery might have influenced the natural history of Crohn's disease (CD). Our aim was to explore the short-term outcome of CD and to specifically assess trends in disease phenotype, medications and surgery in the first five years from diagnosis.
  
  
  METHODS
  A population-based cohort comprising 472 CD patients diagnosed within the primary catchment area of Örebro University Hospital 1963-2005 were identified retrospectively and described. Data on medication, surgery, progression in disease location and behavior, were extracted from the medical records. Patients were divided into three cohorts based on year of diagnosis.
  
  
  RESULTS
  The proportion of patients with complicated disease behavior five years after diagnosis decreased from 54.4% (95%CI, 43.9-65.6) to 33.3% (27.4-40.0) in patients diagnosed 1963-1975 and 1991-2005, respectively (p = 0.002), whereas the proportion of patients progressing to complicated disease behavior was stable among those with non-stricturing, non-penetrating disease at diagnosis (p = 0.435). The proportion of patients undergoing surgery decreased from 65.8% (55.4-76.0) to 34.6% (28.6-41.5) in patients diagnosed 1963-1975 and 1991-2005, respectively (p < 0.001). The reduction in surgery preceded an increased use of immunomodulators and was explained by a decrease in surgery within three months from diagnosis (p = 0.001).
  
  
  CONCLUSIONS
  We observed a striking decrease in complicated disease behavior and surgery five years after CD diagnosis, the latter largely due to a decrease in early surgery. Our findings suggest that the introduction of new treatments alone does not explain the reduction in surgery rates, the increasing proportion of patients with inflammatory disease at diagnosis also play an important role.
authors.affiliation: a Department of Gastroenterology and.
authors.forename: Yaroslava
authors.initials: Y
authors.lastname: Zhulina
authors.affiliation: b Department of Clinical Epidemiology and Biostatistics, Faculty of Medicine and Health , Örebro University , Örebro , Sweden ;
authors.forename: Ruzan
authors.initials: R
authors.lastname: Udumyan
authors.affiliation: a Department of Gastroenterology and.
authors.forename: Curt
authors.initials: C
authors.lastname: Tysk
authors.affiliation: b Department of Clinical Epidemiology and Biostatistics, Faculty of Medicine and Health , Örebro University , Örebro , Sweden ;|c Clinical Epidemiology Unit, Department of Medicine , Karolinska Institutet, Karolinska University Hospital , Stockholm , Sweden ;|d Department of Epidemiology and Public Health , University College London , London , UK.
authors.forename: Scott
authors.initials: S
authors.lastname: Montgomery
authors.affiliation: a Department of Gastroenterology and.
authors.forename: Jonas
authors.initials: J
authors.lastname: Halfvarson
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D010131:Aminosalicylic Acid / Q000627:therapeutic use; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D019819:Budesonide / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003424:Crohn Disease / Q000150:complications / Q000188:drug therapy* / Q000601:surgery*; D013505:Digestive System Surgical Procedures / Q000639:trends; D018450:Disease Progression; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012189:Retrospective Studies; D013548:Sweden; D013997:Time Factors; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D000893:Anti-Inflammatory Agents; D007166:Immunosuppressive Agents; D019819:Budesonide; D010131:Aminosalicylic Acid
keywords: Crohn’s disease; natural history; surgery