{"id":255,"date":"2026-04-23T10:20:34","date_gmt":"2026-04-23T10:20:34","guid":{"rendered":"https:\/\/blogs.bmj.com\/gut\/?p=255"},"modified":"2026-04-23T10:20:34","modified_gmt":"2026-04-23T10:20:34","slug":"gutblog-effect-of-long-term-adherence-on-faecal-immunochemical-test-positivity-rate-positive-predictive-value-and-detection-rate-in-organised-population-based-colorectal-cancer-screening","status":"publish","type":"post","link":"https:\/\/blogs.bmj.com\/gut\/2026\/04\/23\/gutblog-effect-of-long-term-adherence-on-faecal-immunochemical-test-positivity-rate-positive-predictive-value-and-detection-rate-in-organised-population-based-colorectal-cancer-screening\/","title":{"rendered":"#GUTBlog: Effect of long-term adherence on faecal immunochemical test positivity rate, positive predictive value and detection rate in organised population-based colorectal cancer screening"},"content":{"rendered":"

The Editors in chief of GUT, Professors Matias A. Avila, William Grady and Thomas R\u00f6sch, have selected Professor Antoni Castells from the Hospital Clinic de Barcelona and University of Barcelona, Spain, Professor Andrea Buron from the Hospital del Mar Research Institute, Barcelona, Spain and the Research Network on Chronicity, Primary Care and Prevention and Health Promotion (RICAPPS), Madrid, Spain, and Professor Uri Ladabaum from Stanford University School of Medicine, California, USA, to do the next #GUTBlog<\/a>.<\/p>\n

The\u00a0#GUTBlog<\/a> focusses on the paper entitled “Effect of long-term adherence on faecal immunochemical test positivity rate, positive predictive value and detection rate in organised population-based colorectal cancer screening”\u00a0<\/a>which\u00a0was published in paper copy in GUT in May 2026.\u00a0<\/a>Professor Uri Ladabaum is the first author on this paper. Professor Castells is the senior author.\u00a0 Professor Castells and Professor Buron are co-leads at Barcelona\u2019s Colorectal Cancer Screening Program.<\/p>\n

\"\"
\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 From left to right: Professor Antoni Castells, Professor Andrea Buron and Professor Uri Ladabaum<\/figcaption><\/figure>\n

 <\/p>\n

Professor Antoni Castells, Professor Andrea Buron and Professor Uri Ladabaum write:<\/p>\n

“On the 15th Anniversary of the Nationwide Rollout of Catalonia\u2019s Colorectal Cancer Screening Program: <\/strong>Reflections on Population-Wide Faecal Immunochemical Test (FIT)-Based Screening<\/strong><\/p>\n

On March 18, 2026, we celebrated the 15th anniversary of the extension of organised faecal immunochemical test (FIT)-based screening for colorectal cancer (CRC) throughout Catalonia. The event featured the image of a \u201ccastell\u201d (Figure 1) \u2013 a traditional Catalan human tower recognized as an Intangible Cultural Heritage by UNESCO \u2013 as a metaphor for the high level of coordination required among the multiple stakeholders involved in delivering an effective screening program. This celebration, and our recent publication in Gut reporting the effect of long-term adherence on screening results<\/a>, are twin milestones for Catalonia\u2019s program.<\/p>\n

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\u00a0 Figure 1: \u201cLet\u2019s come together to prevent colon and rectal cancer in Barcelona.\u201d (Translated from Catalan)<\/figcaption><\/figure>\n

 <\/p>\n

In 2000, a pioneering pilot CRC screening program was launched across 12 healthcare centers in L\u2019Hospitalet de Llobregat, an industrial city of approximately 239,000 inhabitants within the Barcelona metropolitan area. Using guaiac-based faecal occult blood testing and drawing on seminal evidence generated in the U.S. and England, the initiative set out to answer a critical question: Could a population-based CRC screening program be effectively implemented in Catalonia?<\/p>\n

What followed was a long but determined journey. It took nearly a decade for the Catalan Ministry of Health to endorse the program\u2019s expansion across the region, and a further ten years to achieve full implementation by 2019. Far from being a delay, this timeline reflects the complexity of building a robust, equitable, and sustainable public health intervention at scale. This achievement was made possible by the alignment with European guidelines and, crucially, by an extraordinary collective effort.<\/p>\n

Scientific societies spanning public health, gastroenterology, medical and radiation oncology, occupational health, and pathology worked in close coordination, alongside an engaged civil society represented by patient associations and charitable organizations. Together, they provided the strategic and evidence-based impetus for the public healthcare administration to transform a local pilot into a nationwide program, establishing a model of collaboration and perseverance that continues to save lives \u2013 \u201cFem pinya!\u201d (this Catalan idiom loosely means \u201clet\u2019s come together;\u201d it is the rallying cry for joining the base of the castell to ensure its stability and safety (Figure 1)).<\/p>\n

Catalonia\u2019s CRC Screening Program is publicly funded and promotes equitable access. Eligible men and women aged 50 to 69 are identified through the comprehensive Central Registry of Insured Individuals. Integrated demographic, clinical, endoscopic, and pathological data are captured within a centralized digital platform managed by the Catalan CRC Screening Office \u2013 enhancing traceability and coordination, and providing a powerful foundation for monitoring outcomes and guiding evidence-based decision-making.<\/p>\n

The program is supported by a well-defined organizational structure, with dedicated administrative resources for service delivery, quality assurance, and continuous evaluation. These elements streamline the invitation process, enable rigorous assessment of performance and impact, and foster an ongoing cycle of quality improvement \u2013 positioning the program as a model of effective, data-driven public health implementation. Future priorities include developing a formal communication structure and harnessing resources for dedicated campaigns and local outreach, in order to improve engagement.<\/p>\n

The program is based on mailed biennial FIT invitations, directing eligible individuals to collect the test kit from community pharmacies or primary care centres. Individuals with a positive FIT result are systematically referred to a local digestive disease unit, where a nurse specialized in CRC screening provides tailored counseling on the implications of the positive result, and the benefits and risks of colonoscopy. A diagnostic colonoscopy is promptly scheduled unless there are contraindications.<\/p>\n

In our Gut publication, we analyzed longitudinal adherence at the level of individuals and explored results as a function of adherence. Individuals display a wide range of adherence patterns, whose relationship to CRC outcomes should now be investigated. While the first (\u201cprevalent\u201d) screening round has the highest yield, neoplasia detection settles at clinically meaningful levels beyond the third round, suggesting that screening should continue even in persons with repeatedly normal FIT. No standardized approach has been adopted for reporting longitudinal adherence \u2013 we hope that our reporting and analysis methods are used by other programs, promoting collaborative research.<\/a><\/p>\n

At the 15th anniversary of the program\u2019s nationwide rollout, we acknowledged the urgent challenge of improving participation and longitudinal adherence. We discussed social marketing strategies, innovations in the invitation process, the use of messaging applications for call-recall systems, and electronic alerts for pharmacists and general practitioners to identify invitees who have not yet participated \u2013 there is an opportunity to strengthen our currently limited communication and outreach framework.<\/p>\n

The convergence of the 15th anniversary of Catalonia\u2019s program\u2019s full implementation and our milestone publication in Gut<\/a> illustrate a virtuous cycle of clinical science and dissemination for the benefit of the population feeding and reinforcing each other. Fem pinya!”<\/p>\n","protected":false},"excerpt":{"rendered":"

The Editors in chief of GUT, Professors Matias A. Avila, William Grady and Thomas R\u00f6sch, have selected Professor Antoni Castells from the Hospital Clinic de Barcelona and University of Barcelona, Spain, Professor Andrea Buron from the Hospital del Mar Research Institute, Barcelona, Spain and the Research Network on Chronicity, Primary Care and Prevention and Health […]<\/p>\n

Read More…<\/a><\/p>\n","protected":false},"author":413,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"image","meta":{"footnotes":""},"categories":[6,23],"tags":[],"class_list":["post-255","post","type-post","status-publish","format-image","hentry","category-gutblog","category-endoscopy","post_format-post-format-image"],"_links":{"self":[{"href":"https:\/\/blogs.bmj.com\/gut\/wp-json\/wp\/v2\/posts\/255","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.bmj.com\/gut\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.bmj.com\/gut\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.bmj.com\/gut\/wp-json\/wp\/v2\/users\/413"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.bmj.com\/gut\/wp-json\/wp\/v2\/comments?post=255"}],"version-history":[{"count":0,"href":"https:\/\/blogs.bmj.com\/gut\/wp-json\/wp\/v2\/posts\/255\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.bmj.com\/gut\/wp-json\/wp\/v2\/media?parent=255"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.bmj.com\/gut\/wp-json\/wp\/v2\/categories?post=255"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.bmj.com\/gut\/wp-json\/wp\/v2\/tags?post=255"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}