Differences in colorectal cancer screening rates across income strata by levels of urbanization: results from the Canadian Community Health Survey (2013/2014).

OBJECTIVE: Canadian colorectal cancer screening rates differ across income strata. In the United States, disparities across income strata worsen in rural areas. In Canada, differences in screening across income strata have not been explored by levels of urbanization. This project aimed to estimate up-to-date colorectal cancer (UTD-CRC) screening across income strata by levels of urbanization.

METHODS: Data from the Canadian Community Health Survey (2013/2014) were used to estimate the prevalence of UTD-CRC screening by income quintiles for Canadians aged 50-74 years. UTD-CRC screening was defined as fecal occult blood testing within 2 years or colonoscopy/sigmoidoscopy within 10 years before the survey. Levels of urbanization were defined per Statistics Canada Metropolitan Influenced Zone classifications. Weighted proportions of UTD-CRC screening were calculated and logistic regression was used to assess the effect of income by levels of urbanization.

RESULTS: Self-reported UTD-CRC screening prevalence among Canadians was 52.0%. UTD-CRC screening rates by income ranged from 47.8% (Q1-low) to 54.0% (Q5-high). Across all levels of urbanization, higher income was associated with increased odds of UTD-CRC screening compared to the lowest income quintile (Urban-ORQ5  = 1.49, 95% CI 1.17-1.89; Rural-ORQ5  = 1.42, 95% CI 1.02-1.99; Remote-ORQ5  = 1.54, 95% CI 1.02-2.31). Higher education (ORpost-secondary  = 1.30, 95% CI 1.14-1.49), increasing age (OR70-74  = 2.88, 95% CI 2.39-3.47), and not identifying as an immigrant (OR = 1.45, 95% CI 1.19-1.75) were associated with an increased odds of UTD-CRC screening.

DISCUSSION: Half of Canadians report UTD-CRC screening but across levels of urbanization, higher income was associated with higher screening rates. Efforts are needed to understand and address inequities, particularly among low-income populations.