Socioeconomic Inequalities in Participation in Colorectal Cancer Screening in Ontario, Canada: A Decomposition Analysis

Background: The relationship between socioeconomic status and colorectal cancer screening in Canada remains poorly understood. This study aims to measure and explain the extent of socioeconomic inequalities in colorectal cancer screening participation in Ontario, Canada.Methods: This study assesses socioeconomic inequalities in colorectal cancer screening uptake in Ontario among adults of ages 50 to 74 years (n = 12,039) utilizing cross-sectional data from the 2017 to 2018 Canadian Community Health Survey (CCHS). The Wagstaff index and the Erreygers index were used to quantify and decompose income-related inequality in colorectal cancer screening participation.Results: The results revealed an overall colorectal cancer screening rate of 71.7%, with higher rates among females (78.4%) compared with males (69.4%). The positive values of the Wagstaff index (0.193; 95% confidence interval, 0.170-0.215) and the Erreygers index (0.156; 95% confidence interval, 0.138-0.174) indicated a pro-rich inequality in colorectal cancer screening participation in Ontario (i.e., screening is more concentrated among wealthier individuals). The decomposition analysis identified income (71.61%), education (8.61%), and language barriers with healthcare providers (5.76%) as the primary factors contributing to the observed income-related inequality in colorectal cancer screening participation.Conclusions: Income is the primary driver of socioeconomic inequality, requiring targeted strategies to boost screening rates among low-income residents. Addressing education and language barriers through awareness initiatives and language support can reduce socioeconomic inequalities in cancer screening uptake in Ontario.Impact: Our study reveals significant socioeconomic inequality in colorectal cancer screening in Ontario, driven by income, education, and language barriers, underscoring the need for targeted interventions to promote equitable access.