title: Association between colonic diverticular disease and colorectal cancer: a nationwide population-based study.
abstract: OBJECTIVE
  We investigated whether a diagnosis of colonic diverticular disease is associated with an increased risk for subsequent development of colorectal cancer (CRC) in a nationwide population-based retrospective study.
  
  
  METHODS
  We identified 41,359 individuals diagnosed with colonic diverticular disease as inpatients from 2000 through 2009 from the Taiwan National Health Insurance Research Database (study cohort) and collected data for 165,436 randomly selected additional subjects, matched by sex, age, and baseline year (comparison cohort). Data were collected until individuals developed CRC or withdrew from the National Health Insurance system, or until December 31, 2010. Cumulative incidences and hazard ratios (HRs) of CRC development were determined. To assess for ascertainment bias, we conducted an analysis excluding the first 12 months of follow-up evaluation.
  
  
  RESULTS
  The risk of CRC was significantly higher in the study cohort than in the comparison cohort (HR adjusted for age, sex, and comorbidities, 4.54; 95% confidence interval, 4.19-4.91; P < .0001). In a sensitivity analysis, we excluded the first 12 months of follow-up evaluation after a diagnosis of colonic diverticular disease; subsequent incidence rates for CRC in the study and comparison cohorts were 15.13 and 15.74 per 10,000 person-years, respectively (adjusted HR, 0.96; 95% confidence interval, 0.83-1.11).
  
  
  CONCLUSIONS
  Colonic diverticular disease is not associated with an increased risk of subsequent CRC after the first year of diagnosis of colonic diverticular disease. An increased risk was observed in the first year, possibly owing to misclassification and screening effects.
authors.affiliation: Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Wen-Yen
authors.initials: WY
authors.lastname: Huang
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Che-Chen
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Yee-Min
authors.initials: YM
authors.lastname: Jen
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Yen-Jung
authors.initials: YJ
authors.lastname: Chang
authors.affiliation: Division of Colon and Rectal Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Cheng-Wen
authors.initials: CW
authors.lastname: Hsiao
authors.affiliation: Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan; Division of Hematology-Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Muh-Hwa
authors.initials: MH
authors.lastname: Yang
authors.affiliation: Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Chun-Shun
authors.initials: CS
authors.lastname: Lin
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan; Department of Public Health, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
authors.affiliation: Graduate Institute of Clinical Medicine Science and School of Medicine, College of Medicine, China Medical University Hospital, Taichung, Taiwan; Department of Radiation Oncology, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Ji-An
authors.initials: JA
authors.lastname: Liang
authors.affiliation: Graduate Institute of Clinical Medicine Science and School of Medicine, College of Medicine, China Medical University Hospital, Taichung, Taiwan; Department of Nuclear Medicine and Positron Emission Tomography Center, China Medical University Hospital, Taichung, Taiwan. Electronic address: d10040@mail.cmuh.org.tw.
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology*; D004239:Diverticulitis, Colonic / Q000150:complications*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment; D013624:Taiwan / Q000453:epidemiology
keywords: Colon Cancer; Diverticulitis; Epidemiology; NHIRD