title: Occupational risk for Crohn's disease: A two-center study.
abstract: BACKGROUND
  Occupational factors have been suggested as possible elements in the etiology of Crohn's disease, although evidences have not been fully obtained.
  
  
  OBJECTIVE
  This study is to investigate possible associations between occupation and development of Crohn's disease.
  
  
  METHODS
  This prospective study was carried out in two major hospitals during January 2010 and December 2014. Demographic and clinical data were collected for the calculation of standard incidence ratios and 95% confidence intervals by occupation.
  
  
  RESULTS
  A total of 401 patients with Crohn's disease were recruited into this study. Participants were distributed into 8 major occupational groups, among which "professionists" (17.7%), "service and sales" (18.7%) and "unclassified individuals" (mainly students) (20.2%) took up the most proportions. Increased standard incidence ratios were found in "service and sales" (2.526±0.135, 95% CI: 1.939-3.290), "professionists" (4.216±0.142, 95% CI: 3.194-5.565), and most significantly, in "administrative staffs" (5.476±0.170, 95% CI: 3.926-7.639). In contrast, decreased standard incidence ratios for Crohn's disease were observed in the category of "workers in agriculture, forestry, animal husbandry, fishery and water conservancy" (0.088±0.146, 95% CIs: 0.066-0.117).
  
  
  CONCLUSIONS
  Occupational elements are implicated in the likelihood of development of Crohn's disease.
authors.affiliation: Department of General Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210008, China.
authors.forename: Song
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of General Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210008, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Ding
authors.affiliation: Department of General Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210008, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002, China.
authors.forename: Gefei
authors.initials: G
authors.lastname: Wang
authors.affiliation: Department of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002, China.
authors.forename: Xiuwen
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of General Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210008, China.
authors.forename: Min
authors.initials: M
authors.lastname: Feng
authors.affiliation: Department of General Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210008, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Song
authors.affiliation: Department of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002, China. Electronic address: jiananr@gmail.com.
authors.forename: Jianan
authors.initials: J
authors.lastname: Ren
authors.affiliation: Department of General Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210008, China. Electronic address: guan_wenxian@sina.com.
authors.forename: Wenxian
authors.initials: W
authors.lastname: Guan
mesh_terms: D000328:Adult; D002681:China; D003424:Crohn Disease / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009790:Occupations / Q000145:classification*; D011446:Prospective Studies; D018570:Risk Assessment; D012959:Socioeconomic Factors; D062606:Tertiary Care Centers
keywords: Crohn's disease; Incidence; Inflammatory bowel disease; Occupation; Socioeconomic