title: Prescription drugs associated with false-positive results when using faecal immunochemical tests for colorectal cancer screening.
abstract: BACKGROUND
  The most common side effect in population screening programmes is a false-positive result which leads to unnecessary risks and costs.
  
  
  OBJECTIVE
  To identify factors associated with false-positive results in a colorectal cancer screening programme with the faecal immunochemical test (FIT).
  
  
  METHODS
  Cross-sectional study of 472 participants with a positive FIT who underwent colonoscopy for confirmation of diagnosis between 2013 and 2014. A false-positive result was defined as having a positive FIT (≥20μg haemoglobin per gram of faeces) and follow-up colonoscopy without intermediate/high-risk lesions or cancer.
  
  
  RESULTS
  Women showed a two-fold increased likelihood of a false-positive result compared with men (adjusted OR, 2.3; 95%CI, 1.5-3.4), but no female-specific factor was identified. The other variables associated with a false-positive result were successive screening (adjusted OR, 1.5; 95%CI, 1.0-2.2), anal disorders (adjusted OR, 3.1; 95%CI, 2.1-4.5) and the use of proton pump inhibitors (adjusted OR, 1.8; 95%CI, 1.1-2.9). Successive screening and proton pump inhibitor use were associated with FP in men. None of the other drugs were related to a false-positive FIT.
  
  
  CONCLUSIONS
  Concurrent use of proton pump inhibitors at the time of FIT might increase the likelihood of a false-positive result. Further investigation is needed to determine whether discontinuing them could decrease the false-positive rate.
authors.affiliation: Cancer Prevention and Control Programme, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Gemma
authors.initials: G
authors.lastname: Ibáñez-Sanz
authors.affiliation: Cancer Prevention and Control Programme, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain. Electronic address: mgarcia@iconcologia.net.
authors.forename: Montse
authors.initials: M
authors.lastname: Garcia
authors.affiliation: Department of Gastroenterology, Bellvitge University Hospital-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBEResp), Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Rodríguez-Moranta
authors.affiliation: Cancer Prevention and Control Programme, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBEResp), Spain.
authors.forename: Gemma
authors.initials: G
authors.lastname: Binefa
authors.affiliation: Cancer Prevention and Control Programme, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Gómez-Matas
authors.affiliation: Cancer Prevention and Control Programme, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Xènia
authors.initials: X
authors.lastname: Domènech
authors.affiliation: Cancer Prevention and Control Programme, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Vidal
authors.affiliation: Department of Gastroenterology, Bellvitge University Hospital-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBEResp), Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Soriano
authors.affiliation: Cancer Prevention and Control Programme, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBEResp), Spain; Department of Clinical Sciences, University of Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: Víctor
authors.initials: V
authors.lastname: Moreno
mesh_terms: D000368:Aged; D001004:Anus Diseases / Q000150:complications; D003113:Colonoscopy / Q000379:methods; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D003430:Cross-Sectional Studies; D055088:Early Detection of Cancer / Q000379:methods*; D005189:False Positive Reactions; D005243:Feces / Q000737:chemistry; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D015999:Multivariate Analysis; D009780:Occult Blood; D055553:Prescription Drugs / Q000302:isolation & purification; D054328:Proton Pump Inhibitors / Q000302:isolation & purification*; D012307:Risk Factors; D013030:Spain
chemical_list: D006454:Hemoglobins; D055553:Prescription Drugs; D054328:Proton Pump Inhibitors
keywords: Colorectal cancer screening; Faecal immunochemical test; False positive; Screening