Objective: To compare the association of income and education with breast and cervical cancer screening in Ontario, Canada, and the United States.
Design: Survey using data from the Ontario Health Survey and the US National Health Interview Survey.
Participants: A multistage random sample of women aged 18 years and older living in households in Ontario (N = 23,521) and the United States (N = 23,932) in 1990.
Main outcome measure: Persons were considered screened if they reported a Papanicolaou test within the previous 2 years, a clinical breast examination within the previous year, or a mammogram within the previous year.
Results: Papanicolaou test and clinical breast examination rates were similar between countries, but mammography rates were two to three times higher in the United States across all age groups. Compared with women with less than a high school degree, college graduates were more likely to receive screening (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.2 to 1.7) and there was no difference between countries. Across all procedures, women with higher incomes were more likely to receive screening. For Papanicolaou test and clinical breast examination, there was no difference between countries. Compared with the lowest income, the OR was 1.7 (95% CI, 1.3 to 2.1) in Ontario and 1.9 (95% CI, 1.6 to 2.2) in the United States for Papanicolaou test and 2.1 (95% CI, 1.6 to 2.8) in Ontario and 2.1 (95% CI, 1.8 to 2.6) in the United States for the clinical breast examination for women with income greater than $45,600 (US dollars). For mammography screening, the association of income with use was greater in the United States: the OR was 1.8 (95% CI, 1.3 to 2.6) in Ontario and 2.7 (95% CI, 2.3 to 3.2) in the United States for women with income greater than $45,600 (US dollars).
Conclusions: Despite the long-time presence of universal insurance coverage in Ontario the disparities in the use of cancer screening procedures by the poor were similar to the United States. Universal coverage is not sufficient to overcome the large disparities in screenings across socioeconomic status demonstrated in both countries.