Effectiveness of an organized colorectal cancer screening program on increasing adherence in asymptomatic average-risk Canadians

BACKGROUND Colorectal cancer (CRC) is the third most commonly diagnosed cancer and second highest cause of cancer-related mortality in Canada. Despite the availability of screening services and establishment of guidelines, utilization of colorectal cancer screening in Canada remains low. In 2008, the province of Ontario launched ColonCancerCheck, an organized colorectal cancer screening program aimed at increasing CRC screening adherence. In this study, we adopt a quasi-experimental approach to estimate and describe the impact of ColonCancerCheck on screening behavior in the asymptomatic average risk population. METHODS Annual screening rates from the target population were estimated using five cycles of the Canadian Community Health Survey, a cross-sectional nationally representative survey of health status, healthcare use, and determinants of health in the Canadian population. We used a difference-in-differences design to measure the overall impact of ColonCancerCheck on past-year fecal occult blood testing (FOBT) and endoscopy in Ontario relative to the rest of Canada. Several verification tests validated the suitability of our model specification. RESULTS The difference-in-differences analysis shows that ColonCancerCheck increased FOBT screening in the average risk population by 5.2 percentage points (95% CI [3.2, 7.2]), an increase of 33% relative to pre-program screening rates. The program had no observed effect on endoscopy screening and we found no evidence that ColonCancerCheck differentially altered the screening practices of population sub-groups. CONCLUSIONS Our findings suggest ColonCancerCheck has been successful at increasing use of FOBT in the asymptomatic average risk population.