title: Influence of age at diagnosis on the clinical characteristics of Crohn's disease in Korea: Results from the CONNECT study.
abstract: OBJECTIVE
  The present study evaluated the clinical characteristics of Korean patients with Crohn's disease (CD) according to their age at diagnosis in a nationwide multicenter cohort study.
  
  
  METHODS
  A total of 1224 patients diagnosed with CD between 1982 and 2008 in 32 hospitals were included, and age at diagnosis was categorized as ≤ 16 (G1), 17-40 (G2), 41-59 (G3) and ≥ 60 (G4) years old. The baseline characteristics, medication, and intestinal resection were compared according to the age at diagnosis.
  
  
  RESULTS
  The number of patients in each age group was 155 (G1; 12.7%), 919 (G2; 75.1%), 120 (G3; 9.8%), and 30 (G4; 2.5%). The frequencies of ileocolonic disease in the late adult onset and elderly onset groups were lower than those in the other groups (P < 0.001). The cumulative probabilities of thiopurine and anti-tumor necrosis factor use in late adult onset and elderly onset groups were significantly reduced compared with those of the other groups (P < 0.01). However, the risk of the first intestinal resection was not different among the age groups. The ileal location (hazard ratio [HR]: 1.59; 95% confidence interval [CI]: 1.11-2.27), complicated behavior (HR: 3.35; 95% CI: 2.63-4.27), and early thiopurine use (HR: 0.27; 95% CI: 0.17-0.43) were associated with the first intestinal resection, whereas the age at diagnosis was not a risk factor.
  
  
  CONCLUSIONS
  Elderly onset CD may be related to favorable outcomes in Korea. Thus, the heterogeneity of this disease should be considered when developing a tailored strategy for the treatment of CD.
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea.|Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea.
authors.forename: Sung Wook
authors.initials: SW
authors.lastname: Hwang
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Jee Hyun
authors.identifier: http://orcid.org/0000-0003-1019-6345
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Jong Pil
authors.initials: JP
authors.lastname: Im
authors.affiliation: Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea.
authors.forename: Byong Duk
authors.initials: BD
authors.lastname: Ye
authors.affiliation: Department of Internal Medicine, Konyang University College of Medicine, Daejeon, South Korea.
authors.forename: Hoon Sup
authors.initials: HS
authors.lastname: Koo
authors.affiliation: Department of Internal Medicine, Konyang University College of Medicine, Daejeon, South Korea.
authors.forename: Kyu Chan
authors.initials: KC
authors.lastname: Huh
authors.affiliation: Department of Internal Medicine and Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Jae Hee
authors.initials: JH
authors.lastname: Cheon
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Seoul, South Korea.
authors.forename: You Sun
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Hanyang University College of Medicine, Seoul, South Korea.
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Han
authors.affiliation: Department of Internal Medicine and Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Won Ho
authors.initials: WH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Joo Sung
authors.initials: JS
authors.lastname: Kim
mesh_terms: D000068879:Adalimumab / Q000627:therapeutic use; D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001379:Azathioprine / Q000627:therapeutic use; D015331:Cohort Studies; D003424:Crohn Disease / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology* / Q000601:surgery; D013505:Digestive System Surgical Procedures; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000069285:Infliximab / Q000627:therapeutic use; D007422:Intestines / Q000601:surgery; D008297:Male; D015122:Mercaptopurine / Q000627:therapeutic use; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D011379:Prognosis; D056910:Republic of Korea / Q000453:epidemiology; D013997:Time Factors; D055815:Young Adult
chemical_list: D000069285:Infliximab; D015122:Mercaptopurine; D000068879:Adalimumab; D001379:Azathioprine
keywords: Crohn's disease; age at diagnosis; intestinal resection; medication