Trends in mammography utilization, 1981 to 1994.

From 1981 to 1994, the annual number of mammograms performed in Canada increased from less than 200,000 to more than 1.4 million. By 1994, about three in five women aged 40 and over reported having had a mammogram at some time in their lives. Most of the increase that occurred between 1985 and 1991 was because of greater use of mammography for breast screening. In the early 1990s, the annual numbers and rates stabilized as the number of mammograms performed on a fee-for-service basis declined slightly, while those conducted by provincial/territorial breast screening programs rose. Mammography is increasingly targeted to women aged 5069 for whom screening is considered to be most effective. About 30% of Canadian women aged 50-69 have had a mammogram within the past year, although just one-fifth of these mammograms were obtained through provincial/territorial breast screening programs. Most mammography in Canada is provided through the feefor-service system, although about 80% of fee-for-service mammograms are done for screening purposes, and the remaining 20% for diagnostic assessment. This article is based on administrative data provided by provincial/territorial departments of health and by breast screening programs, as well as on data from the National Population Health Survey. Some implications of mammography utilization for breast cancer incidence and mortality rates are assessed, but because of the long lead time between detection and death, it may be too early to reach definitive conclusions.