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Updated: May 21, 2026
Evaluation of Colorectal Cancer Risk and Prevalence by Stool DNA Integrity Detection
Published on: June 8, 2020
False-positive results from colorectal cancer screening in Catalonia (Spain), 2000-2010
Montse Garcia1, Núria Milà, Gemma Binefa
1Cancer Prevention and Control Group, IDIBELL, L’Hospitalet de Llobregat, Barcelona, Spain. mgarcia@iconcologia.net
Objective:
To identify factors associated with a false-positive result in a population-based colorectal cancer (CRC) screening programme with the faecal occult blood test (FOBT) in Catalonia between 2000 and 2010.
Methods:
The study population consisted of participants of the Catalan CRC screening programme with a positive FOBT who underwent a colonoscopy for diagnostic confirmation from 2000 to 2010. A false-positive result was defined as having a positive test but detecting no high-risk adenoma or cancer in the follow-up colonoscopy. Multivariate logistic regression models were performed to identify sociodemographic and screening variables related to false-positive results. Adjusted odds ratios (OR) and their 95% confidence intervals (CI) were estimated.
Results:
Over the screening period, 1074 (1.7%) of the 63,332 screening tests had a positive result in the Catalan CRC screening programme. The false-positive proportion was 55.2% (n = 546). Women were more likely to have a positive FOBT in the absence of CRC neoplasia than men (adjusted OR = 2.91; 95% CI: 2.22-3.28). During the first prevalence round, the proportion of false-positive results was higher than in subsequent rounds (69.5% vs. 48.9%; P < 0.05). Re-screening and having a bleeding pathology such as haemorrhoids or anal fissures were also associated with a false-positive result.
Conclusion:
The proportion of false-positive results and the associated risks should be estimated to provide an eligible population with more reliable information on the adverse effects of screening.
