title: Factors associated with false-positive and false-negative fecal immunochemical test results for colorectal cancer screening.
abstract: BACKGROUND
  Certain subgroups have higher rates of false fecal immunochemical test (FIT) results, yet few studies have addressed this topic.
  
  
  OBJECTIVE
  To identify demographic factors associated with false-positive and false-negative FIT results in colorectal cancer screening.
  
  
  METHODS
  Retrospective database review of prospectively collected data.
  
  
  METHODS
  A bowel cancer screening center in Hong Kong invited participants for colorectal cancer screening (2008-2012).
  
  
  METHODS
  Study participants who underwent both FIT and colonoscopy in the first year (n = 4482) and underwent colonoscopy after negative FIT results for 3 consecutive years (n = 857).
  
  
  METHODS
  The diagnostic accuracy and predictive values of FIT according to participant characteristics.
  
  
  RESULTS
  The sensitivity, specificity, positive predictive values, and negative predictive values for advanced neoplasia were 33.1%, 91.9%, 19.0%, and 96.0%, respectively. Participants 66 to 70 years of age had higher sensitivity, whereas older age, smoking, and use of aspirin/nonsteroidal anti-inflammatory drugs were associated with lower specificity. The rates of false-positive and false-negative results were 8.1% and 66.9%, respectively. Older age (66-70 years; adjusted odds ratio [AOR] 1.95; 95% confidence interval [CI], 1.35-2.81; P < .001), smoking (AOR 1.68; 95% CI, 1.08-2.61; P = .020), and the presence of polypoid adenoma (AOR 1.71; 95% CI, 1.14-2.57; P = .009) were associated with false-positive results. Younger participants (AOR for elderly participants 0.31) and the use of aspirin/nonsteroidal anti-inflammatory drugs (AOR 4.44) in participants with 1 FIT with negative results and the absence of high-grade dysplasia (AOR for presence 0.41) were associated with false-negative results.
  
  
  CONCLUSIONS
  Self-referred participants who received one type of qualitative FIT.
  
  
  CONCLUSIONS
  These findings could be used to target screening more toward those with a higher risk of false-negative results and those with a lower risk of false-positive results for earlier colonoscopy.
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong, HKSAR, China; School of Public Health and Primary Care, Chinese University of Hong Kong, Shatin, Hong Kong, HKSAR, China.
authors.forename: Martin C S
authors.initials: MC
authors.lastname: Wong
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong, HKSAR, China.
authors.forename: Jessica Y L
authors.initials: JY
authors.lastname: Ching
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong, HKSAR, China.
authors.forename: Victor C W
authors.initials: VC
authors.lastname: Chan
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong, HKSAR, China.
authors.forename: Thomas Y T
authors.initials: TY
authors.lastname: Lam
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong, HKSAR, China.
authors.forename: Arthur K C
authors.initials: AK
authors.lastname: Luk
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong, HKSAR, China.
authors.forename: Simon S M
authors.initials: SS
authors.lastname: Ng
authors.affiliation: Institute of Digestive Disease, Chinese University of Hong Kong, Shatin, Hong Kong, HKSAR, China.
authors.forename: Joseph J Y
authors.initials: JJ
authors.lastname: Sung
mesh_terms: D000236:Adenoma / Q000175:diagnosis; D000328:Adult; D000368:Aged; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D055088:Early Detection of Cancer / Q000379:methods*; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009780:Occult Blood; D012189:Retrospective Studies; D012680:Sensitivity and Specificity