title: Diagnostic yield improves with collection of 2 samples in fecal immunochemical test screening without affecting attendance.
abstract: OBJECTIVE
  The fecal immunochemical test (FIT) is superior to the guaiac-based fecal occult blood test in detecting neoplasia. There are not much data on the optimal number of FITs to perform. We conducted a population-based trial to determine attendance and diagnostic yield of 1- and 2-sample FIT screening.
  
  
  METHODS
  The study included 2 randomly selected groups of subjects aged 50-74 years (1-sample FIT, n=5007; 2-sample FIT, n=3197). The 2-sample group was instructed to collect fecal samples on 2 consecutive days. Subjects were referred for colonoscopy when at least 1 sample tested positive (≥50 ng hemoglobin/mL).
  
  
  RESULTS
  Attendance was 61.5% in the 1-sample group (2979 of 4845; 95% confidence interval, 60.1%-62.9%) and 61.3% in the 2-sample group (1875 of 3061; 95% confidence interval, 59.6%-63.0%; P=.84). In the 1-sample group 8.1% tested positive, and in the 2-sample group 12.8% had at least 1 positive test outcome and 5.0% had 2 positive test outcomes (P<.05). When the mean from both test results in the 2-sample group was used, 10.1% had a positive test outcome (P<.05). The detection rates for advanced neoplasia were 3.1% in the 1-sample group, 4.1% in the 2-sample group with at least 1 positive test outcome, 2.5% when both test results were positive, and 3.7% among subjects with the mean from both test results being positive.
  
  
  CONCLUSIONS
  There is no difference in attendance for subjects offered 1- or 2-sample FIT screening. The results allow for the development of efficient FIT screening strategies that can be adapted for local colonoscopy capacities, rather than varying the cut-off value in a 1-sample strategy.
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus University Medical Centre, Rotterdam, The Netherlands. a.vanroon@erasmusmc.nl
authors.forename: Aafke H C
authors.initials: AH
authors.lastname: van Roon
authors.forename: Janneke A
authors.initials: JA
authors.lastname: Wilschut
authors.forename: Lieke
authors.initials: L
authors.lastname: Hol
authors.forename: Marjolein
authors.initials: M
authors.lastname: van Ballegooijen
authors.forename: Jacqueline C I Y
authors.initials: JC
authors.lastname: Reijerink
authors.forename: Hans
authors.initials: H
authors.lastname: 't Mannetje
authors.forename: Laura J C
authors.initials: LJ
authors.lastname: Kranenburg
authors.forename: Katharina
authors.initials: K
authors.lastname: Biermann
authors.forename: Anneke J
authors.initials: AJ
authors.lastname: van Vuuren
authors.forename: Jan
authors.initials: J
authors.lastname: Francke
authors.forename: Alexandra C M
authors.initials: AC
authors.lastname: van der Togt
authors.forename: Dik J F
authors.initials: DJ
authors.lastname: Habbema
authors.forename: Monique E
authors.initials: ME
authors.lastname: van Leerdam
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Kuipers
mesh_terms: D000368:Aged; D019411:Clinical Laboratory Techniques / Q000379:methods*; D005243:Feces / Q000737:chemistry*; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis*; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007120:Immunochemistry / Q000379:methods*; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011897:Random Allocation; D012680:Sensitivity and Specificity
chemical_list: D006454:Hemoglobins