Up-to-date on cancer screening among Ontario patients seen by walk-in clinic physicians: a retrospective cohort study

Walk-in clinics are typically viewed as high-volume locations for managing acute issues but also may serve as a location for primary care, including cancer screening, for patients without a family physician. In this population-based cohort study, we compared breast, cervical and colorectal cancer screening up-to-date status for people living in the Canadian province of Ontario who were formally enrolled to a family physician versus those not enrolled but who had at least one encounter with a walk-in clinic physician in the previous year. Using provincial administrative databases, we created two mutually exclusive groups: i) those who were formally enrolled to a family physician, ii) those who were not enrolled but had at least one visit with a walk-in clinic physician from April 1, 2019 to March 31, 2020. We compared up to date status for three cancer screenings as of April 1, 2020 among screen-eligible people. We found that people who were not enrolled and had seen a walk-in clinic physician in the previous year consistently were less likely to be up to date on cancer screening than Ontarians who were formally enrolled with a family physician (46.1% vs. 67.4% for breast, 45.8% vs. 67.4% for cervical, 49.5% vs. 73.1% for colorectal). They were also more likely to be foreign-born and to live in structurally marginalized neighbourhoods. New methods are needed to enable screening for people who are reliant on walk-in clinics and to address the urgent need in Ontario for more primary care providers who deliver comprehensive, longitudinal care.