Intellectual Disability Linked to Lower CRC Screening Rates | Healio Gastroenterology

Colorectal cancer screening rates are significantly lower among individuals with intellectual disabilities, and even when they do participate, they face greater challenges in completing the process, according to a recent Danish study published in JAMA Network Open. The findings, released March 25, 2026, underscore a critical disparity in healthcare access and highlight the require for tailored strategies to improve equitable outcomes for this vulnerable population. Whereas colorectal cancer is often preventable with timely screening, individuals with intellectual disabilities are diagnosed at later stages and experience higher mortality rates from the disease.

Disparities in Screening Participation

The study, led by Trine Allerslev Horsbøl, PhD, and colleagues at the National Institute of Public Health at University of Southern Denmark, analyzed data from over 166,000 adults born between 1940 and 1973. Researchers compared screening participation and completion of diagnostic examinations following a positive stool sample result between individuals with and without intellectual disabilities. Denmark offers a free, biennial colorectal cancer screening program to all residents aged 50 to 74, utilizing fecal immunochemical testing (FIT) – a stool-based test – as the initial screening method. Participation in screening is crucial for early detection, but the study revealed a substantial gap in uptake.

Individuals without intellectual disabilities were significantly more likely to return a stool sample within 90 days of receiving an invitation (56.1%) compared to those with intellectual disabilities (30.2%). Those without intellectual disabilities were more likely to undergo a diagnostic examination, such as a colonoscopy, after a positive FIT result (90.2% vs. 70.5%). These differences highlight systemic barriers preventing individuals with intellectual disabilities from fully benefiting from available screening programs.

Severity of Disability and Screening Completion

Interestingly, the study also examined the relationship between the severity of intellectual disability and screening outcomes. Researchers categorized intellectual disability as mild, moderate, severe, or profound. They found that while individuals with more severe intellectual disabilities were more likely to return a stool sample, they were less likely to complete the diagnostic examination process following a positive result.

“An unexpected finding was that people with more severe intellectual disabilities were more likely to submit stool samples than people with milder disabilities, and that their samples are more often usable,” explained Dr. Horsbøl in an interview with Healio. She posited that this may be due to the fact that individuals with more severe disabilities often reside in residential care facilities where staff can assist with sample collection and submission. Conversely, those with milder disabilities may live independently and face greater challenges managing the process themselves.

Challenges Beyond Initial Screening

The study also revealed difficulties with the colonoscopy procedure itself for individuals with intellectual disabilities. A significantly higher proportion experienced incomplete colonoscopies (28.2% vs. 13.8%), potentially due to inadequate bowel preparation. A greater percentage of stool samples submitted by individuals with intellectual disabilities were deemed unsuitable for analysis (1.8% vs. 0.4%).

“We expected lower screening participation among individuals with intellectual disability but were surprised by the magnitude of the disparity,” Dr. Horsbøl noted. “Even when individuals with intellectual disability did participate, they more often encountered challenges with stool sample collection and colonoscopy completion.”

Why This Matters: Increased Risk and Delayed Diagnosis

Individuals with intellectual disabilities face a higher incidence of colorectal cancer and a two-fold increase in mortality rates compared to the general population. Colorectal cancer is often preventable with early detection, but delayed diagnosis is a significant contributing factor to poorer outcomes in this population. Increased prevalence of risk factors, such as obesity and physical inactivity, may also play a role. The current study suggests that disparities in screening participation contribute to these inequalities.

Understanding the Screening Process and FIT Testing

Colorectal cancer screening aims to detect precancerous polyps, which can be removed before they develop into cancer, or to identify cancer at an early, more treatable stage. FIT testing, the initial screening method used in the Danish study, involves analyzing a slight stool sample for hidden blood. A positive FIT result does not necessarily indicate cancer, but it warrants further investigation, typically through a colonoscopy. A colonoscopy involves inserting a flexible tube with a camera into the rectum to visualize the entire colon and remove any suspicious polyps. Follow-up after a positive FIT result is critical to ensure timely diagnosis and treatment.

Implications for Public Health and Future Strategies

The findings from this study have important implications for public health initiatives aimed at reducing colorectal cancer disparities. Dr. Horsbøl emphasizes the need for targeted interventions to address the specific barriers faced by individuals with intellectual disabilities. This includes providing adequate support with the practical aspects of screening, such as stool sample collection and bowel preparation for colonoscopy, as well as ensuring informed decision-making about participation.

“The results suggest that within the group of people with intellectual disabilities there are more individuals who need support with the practical parts of the process, including collecting the stool sample and preparing for the colonoscopy,” Dr. Horsbøl stated. “It’s important to ensure that an individual’s decision not to participate in the screening [program] is based on a well-informed choice.”

Future strategies should prioritize accessible communication, individualized support, and collaboration between healthcare providers, caregivers, and support staff to improve equitable access to colorectal cancer screening for all.

Trine Allerslev Horsbøl, PhD, can be reached at [email protected].