title: Accuracy of faecal occult blood test and Helicobacter pylori stool antigen test for detection of upper gastrointestinal lesions.
abstract: OBJECTIVE
  Highly sensitive guaiac-based faecal occult blood (Hemoccult SENSA) and Helicobacter pylori stool antigen testing might help detect upper gastrointestinal lesions when appended to a colorectal cancer screening programme with faecal immunochemical testing. We evaluated the diagnostic accuracies of two stool tests in detecting upper gastrointestinal lesions.
  
  
  METHODS
  Cross-sectional design.
  
  
  METHODS
  Hospital-based and community-based screening settings.
  
  
  METHODS
  A hospital-based deviation cohort of 3172 participants to evaluate test performance and a community-based validation cohort of 3621 to verify the findings.
  
  
  METHODS
  Three types of stool tests with bidirectional endoscopy as the reference standard.
  
  
  RESULTS
  Sensitivity, specificity and positive and negative likelihood ratios.
  
  
  RESULTS
  For detecting upper gastrointestinal lesions in cases with negative immunochemical tests, the sensitivity, specificity, and positive and negative likelihood ratios of the guaiac-based and H pylori antigen tests were 16.3% (95% CI 13.3% to 19.8%), 90.1% (88.9% to 91.2%), 1.64 (1.31 to 2.07), and 0.93 (0.89 to 0.97), respectively, and 52.5% (48.1% to 56.9%), 80.6% (79.0% to 82.1%), 2.71 (2.41 to 3.04) and 0.59 (0.54 to 0.65), respectively. For detecting upper gastrointestinal lesions in cases with normal colonoscopy, the results of the guaiac-based and H pylori antigen tests were 17.9% (14.8% to 21.5%), 90.1% (88.9% to 91.2%), 1.81 (1.45 to 2.26) and 0.91 (0.87 to 0.95), respectively, and 53.1% (48.6% to 57.4%), 80.7% (79.1% to 82.2%), 2.75 (2.45 to 3.08) and 0.58 (0.53 to 0.64), respectively. Within the community, positive predictive values of the immunochemical and H pylori antigen tests were 36.0% (26.0% to 46.0%) and 31.9% (28.3% to 35.5%), respectively, for detecting lower and upper gastrointestinal lesions, which were similar to expected values.
  
  
  CONCLUSIONS
  The H pylori stool antigen test is more accurate than the guaiac-based test in the screening of upper gastrointestinal lesions in a population with high prevalence of H pylori infection and upper gastrointestinal lesions. It is applicable to add the H pylori antigen test to the immunochemical test for pan detection.
  
  
  BACKGROUND
  NCT01341197 (ClinicalTrial.gov).
authors.affiliation: Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Yi-Chia
authors.initials: YC
authors.lastname: Lee
authors.forename: Han-Mo
authors.initials: HM
authors.lastname: Chiu
authors.forename: Tsung-Hsien
authors.initials: TH
authors.lastname: Chiang
authors.forename: Amy Ming-Fang
authors.initials: AM
authors.lastname: Yen
authors.forename: Sherry Yueh-Hsia
authors.initials: SY
authors.lastname: Chiu
authors.forename: Sam Li-Sheng
authors.initials: SL
authors.lastname: Chen
authors.forename: Jean Ching-Yuan
authors.initials: JC
authors.lastname: Fann
authors.forename: Yen-Po
authors.initials: YP
authors.lastname: Yeh
authors.forename: Chao-Sheng
authors.initials: CS
authors.lastname: Liao
authors.forename: Tsung-Hui
authors.initials: TH
authors.lastname: Hu
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Tu
authors.forename: Ping-Huei
authors.initials: PH
authors.lastname: Tseng
authors.forename: Chien-Chuan
authors.initials: CC
authors.lastname: Chen
authors.forename: Mei-Jyh
authors.initials: MJ
authors.lastname: Chen
authors.forename: Jyh-Ming
authors.initials: JM
authors.lastname: Liou
authors.forename: Wei-Chih
authors.initials: WC
authors.lastname: Liao
authors.forename: Yo-Ping
authors.initials: YP
authors.lastname: Lai
authors.forename: Chen-Ping
authors.initials: CP
authors.lastname: Wang
authors.forename: Jenq-Yuh
authors.initials: JY
authors.lastname: Ko
authors.forename: Hsiu-Po
authors.initials: HP
authors.lastname: Wang
authors.forename: Hung
authors.initials: H
authors.lastname: Chiang
authors.forename: Jaw-Town
authors.initials: JT
authors.lastname: Lin
authors.forename: Hsiu-Hsi
authors.initials: HH
authors.lastname: Chen
authors.forename: Ming-Shiang
authors.initials: MS
authors.lastname: Wu
keywords: GASTROENTEROLOGY