The Canada Health Monitor is a syndicated telephone survey of Canadians 15 years of age and older conducted semi-annually by me and Price Waterhouse and administered by the Price Waterhouse National Research Centre in Ottawa. Sample sizes for individual surveys range from 2200 to 2700 people.
The sample design is a stratified, random sample representing the distribution of the population 15 years of age and older by community size, sex and age in each of the 10 provinces.
We thank Dr. Elizabeth Kaegi, former director of medical affairs of the Canadian Cancer Society and the National Cancer Institute of Canada, for helping us incorporate the screening guidelines into our research.
Our findings include the following. (Margins of error (ME) given are those for a 95% confidence interval.)
Among women 50 to 69 years of age (n = 380, ME ± 5), the proportion who reported having had a mammogram within the previous 2 years increased from 54% in 1992 (survey no. 7) to 70% in 1995 (survey no. 11). During the same period, the proportion of women 50 to 59 years of age who reported never having had a mammogram decreased from 30% to 17% (Fig. 1). Among women of all ages who had had a mammogram within the previous 12 months, and who did not have a previously diagnosed problem (survey no. 10, n = 224), 5% reported that the mammogram revealed a problem that required medical attention (ME ± 3); among women 50 to 69 (n = 109, ME ± 6), 9% reported that the mammogram revealed a problem.
In 1992 (survey no. 7), women 50 to 69 who had not had a mammogram in 3 years or more, or had never been tested (n = 149, ME ± 8), were asked to select which of a variety of reasons for not being screened applied to them. The most commonly selected reasons were: "The tests were not necessary for someone who was healthy" (33%), "The doctor felt it was unnecessary" (21%), "The tests were unpleasant or hurt" (19%) and "It was hard to take time off work" (15%).
In 1994 (survey no. 11), two thirds of women 50 to 69 who had not been tested for 3 years or more, or had never been tested, and who reported a family history of cancer, said that their physician had not discussed with them how often they should have a mammogram (survey no. 11, n = 52, ME ± 13.5). This group included 14 women who reported a family history of breast cancer and 45 women who reported a family history of other types of cancer. We did not indicate lung cancer as a special category.
Of all women who had not been tested in 3 years or more, or had never been tested, and had a family history of cancer, 80% reported that their physician had not discussed with them how often they should have a mammogram (survey no. 11, n = 438, ME ± 4). Among the women in this group with a family history of breast cancer (n = 129), 69% reported their doctor had not discussed the matter with them (ME ± 8.5). Among all women with a family history of cancer who had not had a Papanicolaou smear performed in 3 years or more (survey no. 11, n = 361, ME ± 4.5), 74% reported that their physician had not discussed with them how often they should have the test; the result was similar among those who also had one or more sexual partners (n = 142).
These data -- even after discounting for margin of error and the possibility of biased or inaccurate responses -- suggest that many women at risk are not being appropriately advised by their physician. The growing proportion of women 50 to 69 years old who report having undergone mammography screening within the guideline period is good news.
Earl Berger PhD, CMC
Managing director
Canada Health Monitor
Toronto, Ont.