title: Association Between Colorectal Cancer Mortality and Gradient Fecal Hemoglobin Concentration in Colonoscopy Noncompliers.
abstract: To what extent the risk for colorectal cancer (CRC) death among noncompliers of colonoscopy is elevated following positive fecal immunological testing and whether the elevated risk varies with the fecal hemoglobin concentration (f-Hb) and location of CRC have not been researched.
  
  
  
  We used data on 59 389 individuals (4.0%) among 1 489 937 Taiwanese screenees age 50 to 69 years with f-Hb 20 μg hemoglobin or more per gram of feces from 2004 to 2009. They were classified into 41 995 who received colonoscopy and 10 778 who received no confirmatory examination; the latter was categorized into three risk groups according to f-Hb (20-49, 50-99, and 100+). Mortality from CRC as the primary end point was monitored until December 31, 2012.
  
  
  
  A 1.64-fold (95% confidence interval [CI] = 1.32 to 2.04) increased risk for CRC death for the noncolonoscopy group as opposed to the colonoscopy group adjusting for differences in baseline characteristics. A gradient relationship was noted between cumulative mortality and age- and sex-adjusted f-Hb categories with 1.31-fold (95% CI = 1.04 to 1.71), 2.21-fold (95% CI = 1.55 to 3.34), and 2.53-fold (95% CI = 1.95 to 3.43) increased risk, respectively, for the 20-49, 50-99, and 100+ risk groups in the noncolonoscopy group compared with the colonoscopy group. The noncolonoscopy group led to a statistically significant 1.75-fold increased risk (95% CI = 1.35 to 2.33) for CRC of the distal colon but a statistically nonsignificant 1.11-fold increased risk (95% CI = 0.70 to 1.75) for the proximal colon, compared with the colonoscopy group. When the comparator was limited to subjects whose colonoscopy was completed to the cecum, the statistically significantly elevated risk for CRC mortality was seen for both distal and proximal colon in the noncolonoscopy group.
  
  
  
  After a positive fecal immunochemical test, colonoscopy can reduce by about half the number of deaths from CRC. Among colonoscopy noncompliers, higher f-Hb is associated with an increased risk of mortality from CRC in a dose-response manner.
authors.affiliation: Department of Internal Medicine, National Taiwan University, Taipei, Taiwan.|College of Medicine,  Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Yi-Chia
authors.initials: YC
authors.lastname: Lee
authors.affiliation: School of Oral Hygiene, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Sam
authors.initials: S
authors.lastname: Li-Sheng Chen
authors.affiliation: School of Oral Hygiene, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Amy
authors.initials: A
authors.lastname: Ming-Fang Yen
authors.affiliation: Department and Graduate Institute of Health Care Management, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Sherry
authors.initials: S
authors.lastname: Yueh-Hsia Chiu
authors.affiliation: Department of Health Industry Management, Kainan University, Tao-Yuan, Taiwan
authors.forename: Jean
authors.initials: J
authors.lastname: Ching-Yuan Fann
authors.affiliation: College of Medicine,  Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Shu-Lin
authors.initials: SL
authors.lastname: Chuang
authors.affiliation: Department of Internal Medicine, National Taiwan University, Taipei, Taiwan.|Graduate Institute of Clinical Medicine, National Taiwan University, Taipei, Taiwan.|Department of Integrated Diagnostics and Therapeutics, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Tsung-Hsien
authors.initials: TH
authors.lastname: Chiang
authors.affiliation: Department of Internal Medicine, National Taiwan University, Taipei, Taiwan.|Division of Gastroenterology and Hepatology, Chia-Yi Christian Hospital, Chia-Yi, Taiwan.
authors.forename: Chu-Kuang
authors.initials: CK
authors.lastname: Chou
authors.affiliation: Department of Internal Medicine, National Taiwan University, Taipei, Taiwan.|College of Medicine,  Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Han-Mo
authors.initials: HM
authors.lastname: Chiu
authors.affiliation: Department of Internal Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Ming-Shiang
authors.initials: MS
authors.lastname: Wu
authors.affiliation: Health Promotion Administration, Ministry of Health and Welfare, Taiwan.
authors.forename: Chien-Yuan
authors.initials: CY
authors.lastname: Wu
authors.affiliation: Health Promotion Administration, Ministry of Health and Welfare, Taiwan.
authors.forename: Shu-Li
authors.initials: SL
authors.lastname: Chia
authors.affiliation: Health Promotion Administration, Ministry of Health and Welfare, Taiwan.|Institute of Public Health, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Shu-Ti
authors.initials: ST
authors.lastname: Chiou
authors.affiliation: College of Medicine,  Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Hsiu-Hsi
authors.initials: HH
authors.lastname: Chen
mesh_terms: D000368:Aged; D003106:Colon / Q000473:pathology; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000401:mortality* / Q000473:pathology; D005243:Feces / Q000737:chemistry*; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009780:Occult Blood; D010349:Patient Compliance / Q000706:statistics & numerical data*; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology
chemical_list: D006454:Hemoglobins