Correlates of non-adherence to breast, cervical, and colorectal cancer screening among screen-eligible women: a population-based cohort study in Ontario, Canada

Purpose Breast, cervical, and colorectal cancers are cancers that can be detected early through screening. Despite organized cancer screening programs in Ontario, Canada participation remains low among marginalized populations. Although extensive research has been done about factors contributing to under-screening by cancer site, the predictors of under/never screened conjointly for all three types of cancer remain unknown. Methods Using provincial-level linked administrative data sets, we examined Ontario women who were screen-eligible for all three types of cancer over a 36-month period (i.e., April 2014-March 2017) and determined how many were up to date on 0, 1, 2, and all three types of screenings. Multivariate logistic regression was utilized to examine individual and structural predictors of screening with the group overdue for all screening being the reference group. Results Of the 1,204,551 screen-eligible women, 15% were overdue for all. Living in the lowest income neighborhoods (AOR 0.46 [95% CI 0.45-0.47]), being recent immigrants (AOR 0.54 [95% CI 0.53-0.55]), having no primary care provider (AOR 0.17 [95% CI 0.16-0.17]), and having no contact with health care services (AOR 0.09 [95% CI 0.09-0.09]) significantly increased the likelihood of being overdue for all versus no screening type. Conclusions Considering that more than 15% of screen-eligible women in Ontario were overdue for all types of cancer screening, it is imperative to address structural barriers such as lack of a primary care provider. Innovative interventions like "one-stop shopping" where screening for different cancers can be offered at the same time could promote screening uptake.