title: Effect of aspirin and antiplatelet drugs on the outcome of the fecal immunochemical test.
abstract: OBJECTIVE
  To evaluate the effect of aspirin and nonaspirin antiplatelet agents (NAAAs) on the performance of the fecal immunochemical test (FIT).
  
  
  METHODS
  We performed a post hoc analysis of results from a clinical trial that involved 28,696 asymptomatic average-risk men and women aged 50 to 69 years invited to participate in a colorectal cancer screening program with FIT between November 1, 2008, and June 31, 2011.
  
  
  RESULTS
  The test was returned by 6390 individuals (22.3%), of whom 5821 (91.1%) reported not using antiplatelet drugs (nonusers group) and 569 (8.9%) reported using these drugs at the time of testing (users group). The FIT result was positive in 48 of 569 users (8.4%) and 365 of 5821 nonusers (6.3%) (P=.05). A positive FIT result was found in 7.3% (28/384) of aspirin users, 7.1% (10/140) of NAAA users, and 22.2% (10/45) of those undergoing dual antiplatelet therapy (DAPT) (aspirin plus an NAAA). The DAPT subgroup had a significantly higher positive FIT rate than the nonuser group (odds ratio, 3.5; 95% CI, 1.7-7.3; P<.05). The positive predictive value (PPV) for advanced neoplasia (AN) in nonusers was 50.4% vs 50.0% in users (P = .40). The PPV for AN was 57.0% in aspirin users, 30.0% in NAAA users, and 50.0% in DAPT users, without statistically significant differences between the user and nonuser groups.
  
  
  CONCLUSIONS
  The use of DAPT increased the rate of positive FIT results. Use of aspirin, NAAAs, or both did not modify the PPV for AN in this population-based colorectal screening program.
authors.affiliation: Department of Gastroenterology, Hospital Donostia, Instituto Biodonostia, Centro de Investigación Biomédica en Red en Enfermedades Hepáticas y Digestivas, Universidad del País Vasco, San Sebastián, Spain. Electronic address: medik@telefonica.net.
authors.forename: Luis
authors.initials: L
authors.lastname: Bujanda
authors.forename: Ángel
authors.initials: Á
authors.lastname: Lanas
authors.forename: Enrique
authors.initials: E
authors.lastname: Quintero
authors.forename: Antoni
authors.initials: A
authors.lastname: Castells
authors.forename: Cristina
authors.initials: C
authors.lastname: Sarasqueta
authors.forename: Joaquín
authors.initials: J
authors.lastname: Cubiella
authors.forename: Vicent
authors.initials: V
authors.lastname: Hernandez
authors.forename: Juan D
authors.initials: JD
authors.lastname: Morillas
authors.forename: Teresa
authors.initials: T
authors.lastname: Perez-Fernández
authors.forename: Dolores
authors.initials: D
authors.lastname: Salas
authors.forename: Montserrat
authors.initials: M
authors.lastname: Andreu
authors.forename: Fernando
authors.initials: F
authors.lastname: Carballo
authors.forename: Xavier
authors.initials: X
authors.lastname: Bessa
authors.forename: Angel
authors.initials: A
authors.lastname: Cosme
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Jover
mesh_terms: D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007120:Immunochemistry / Q000379:methods; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data*; D008875:Middle Aged; D009780:Occult Blood; D017063:Outcome Assessment, Health Care; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D015203:Reproducibility of Results; D012307:Risk Factors
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D010975:Platelet Aggregation Inhibitors; D001241:Aspirin