Impact of organized colorectal cancer screening programs on screening uptake and screening inequalities: A study of systematic- and patient-reliant programs in Canada

Abstract

BackgroundVarious provincial colorectal cancer screening programs have been implemented in Canada but have yet to be evaluated. ObjectiveWe examined the effects of patient-reliant and systematic organized colorectal screening programs on colorectal cancer screening uptake and on screening inequalities by income, education, rural residence, and access to a primary care physician. MethodsLifetime and recent (< 1, <2 years) stool-based screening uptake were assessed among Canadian Community Health Survey respondents (cycles 2003–2014), aged 50–75 years, with no personal or family history of colorectal cancer. We used a difference-in-differences approach to estimate the effects of two systematic provincial programs (where all eligible residents receive screening kits via mail), and one patient-reliant program (where residents receive screening kits via mail following their request to a physician, phone line or website). ResultsOverall, systematic and patient-reliant programs were associated with a 4- [95 % CI: 1%, 7%] and a 12-percentage point [95 % CI: 2%, 8%] increase in recent (<2 years) stool-based screening, respectively, with effect sizes converging after three years at approximately 10 %. The patient-reliant program was associated with an 11 % [95 % CI: 5%, 17 %] increase in uptake among those with a physician, but no effect among those without—leading to increased inequality in uptake according to physician access. InterpretationBoth program types increase colorectal screening overall. Reliance on patients’ request for screening may increase disparities according to physician access. Exploration of complementary targeted interventions in patient-reliant settings appears warranted.