Background: Alberta’s colorectal cancer (CRC) screening clinical practice guideline recommends that average?risk individuals aged 50–74 undergo fecal immunochemical testing (FIT) every 1–2 years, with abnormal results followed by colonoscopy within 8 weeks. Despite these recommendations, provincial FIT participation and colonoscopy follow?up rates remain below the targets of 60% and >=98% (within 12 months), respectively. One contributing factor is the inclusion of individuals with higher?than?average CRC risk in the measurement denominator.
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Objectives: The objectives of this project are to: (i) improve the accuracy of FIT participation and colonoscopy follow?up indicators by refining the denominator (exclude individuals at higher risk), and (ii) assess disparities in screening participation and colonoscopy follow up across key demographic groups.
Methods: We identified individuals aged 50–72 years as of January?2021 (index date). Using linkages across multiple health administrative datasets—including outpatient, inpatient, cancer registry, and screening participation data—we excluded those with a history of high?risk conditions (invasive or in?situ colorectal cancer, inflammatory bowel disease, total colectomy) and those who had undergone colonoscopy or sigmoidoscopy within the previous five years. Participants were followed through December?2023 to ascertain fecal immunochemical test (FIT) completion. Individuals with positive FIT results were then followed for up to 12 months or until December?2024, whichever occurred first.
Findings: A total of 1,212,087 individuals aged 50-72 years at index date were included in the analysis. After exclusion of individuals at higher-than-average risk, FIT participation increased by 3.5% (unrefined:38.8%, refined: 42.3%) and colonoscopy follow up rate at 12 months increased by 3.5% (unrefined:75%, refined 78.5%).   Upon refinement, FIT participation showed a linear increase by age (50-54 years:38%, 70-72 years: 46%).  Females (44%) showed a higher participation compared to males (40.6%). North Zone (36.3%) and Central Zone (39.3%) had a lower participation compared to South Zone (43.3%), Calgary Zone (42.8%) and Edmonton Zone (44.5%). Those living in the rural areas (38.3%) had a lower participation compared to urban areas (40.7%) and metro areas (43.8%). Individuals who immigrated to Alberta in the last 10 years had a much lower participation (36.5%) compared to those who had been continuously living in Alberta for at least 10 years (43.2%). Colonoscopy follow up showed a similar disparity pattern except that Edmonton Zone had a much lower colonoscopy follow up rate (70.8%) compared to North (78.7%), Central (80.7%), Calgary (84.4%) and South Zone (82.6%) even after refining the denominator.
Conclusion: Refining the denominator to exclude individuals at higher?than?average risk improved provincial estimates of FIT participation and colonoscopy follow?up. We identified disparities by age, sex, geographic zone, migration status, and urban–rural residence. These findings can inform more precise analytic approaches, help reduce avoidable inequities, and support targeted outreach efforts to enhance FIT participation and timely colonoscopy follow?up across the province.