RT Journal Article SR Electronic T1 Characteristics of primary care practices by proportion of patients unvaccinated against SARS-CoV-2: a cross-sectional cohort study JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E432 OP E440 DO 10.1503/cmaj.230816 VO 196 IS 13 A1 Shuldiner, Jennifer A1 Green, Michael E. A1 Kiran, Tara A1 Khan, Shahriar A1 Frymire, Eliot A1 Moineddin, Rahim A1 Kerr, Meghan A1 Tadrous, Mina A1 Nowak, Dominik Alex A1 Kwong, Jeffrey C. A1 Hu, Jia A1 Witteman, Holly O. A1 Hamilton, Bryn A1 Bogoch, Isaac A1 Marshall, Lydia-Joy A1 Ikura, Sophia A1 Bar-Ziv, Stacey A1 Kaplan, David A1 Ivers, Noah YR 2024 UL http://www.cmaj.ca/content/196/13/E432.abstract AB Background: Variations in primary care practices may explain some differences in health outcomes during the COVID-19 pandemic. We sought to evaluate the characteristics of primary care practices by the proportion of patients unvaccinated against SARS-CoV-2.Methods: We conducted a population-based, cross-sectional cohort study using linked administrative data sets in Ontario, Canada. We calculated the percentage of patients unvaccinated against SARS-CoV-2 enrolled with each comprehensive-care family physician, ranked physicians according to the proportion of patients unvaccinated, and identified physicians in the top 10% (v. the other 90%). We compared characteristics of family physicians and their patients in these 2 groups using standardized differences.Results: We analyzed 9060 family physicians with 10 837 909 enrolled patients. Family physicians with the largest proportion (top 10%) of unvaccinated patients (n = 906) were more likely to be male, to have trained outside of Canada, to be older, and to work in an enhanced fee-for-service model than those in the remaining 90%. Vaccine coverage (≥ 2 doses of SARS-CoV-2 vaccine) was 74% among patients of physicians with the largest proportion of unvaccinated patients, compared with 87% in the remaining patient population. Patients in the top 10% group tended to be younger and live in areas with higher levels of ethnic diversity and immigration and lower incomes.Interpretation: Primary care practices with the largest proportion of patients unvaccinated against SARS-CoV-2 served marginalized communities and were less likely to use team-based care models. These findings can guide resource planning and help tailor interventions to integrate public health priorities within primary care practices.