Screening Mammography Program of British Columbia: Pattern of use and health care system costs

Background: The use of mammography for screening asymptomatic women has inc reased dramatically in the past decade. This report describes the changes t hat have occurred in the use of bilateral mammography in British Columbia s ince the provincial breast cancer screening program began in 1988. Methods: Using province-wide databases from both the breast cancer screenin g program and the provincial health insurance plan in BC, the authors deter mined the number and costs of bilateral mammography services for women aged 40 years or older between Apr. 1, 1986, and Mar. 31, 1997. Unilateral mamm ography was excluded because it is used for investigating symptomatic disea se and screening abnormalities, and for follow-up of women who have undergo ne mastectomy for cancer. Results: As the provincial breast cancer screening program expanded from 1 site in 1988 to 23 in 1997, it provided an increasing proportion of the bil ateral mammographic examinations carried out each year in BC. In fiscal yea r 1996/97, 65%:of bilateral mammographic examinations were performed throug h the screening program. The cost per examination within the screening prog ram dropped as volume increased. Thirty percent more bilateral mammography examinations were done in 1996/97 than in 1991/92, but health care system e xpenditures for these services increased by only 4% during the same period. In calendar year 1996, 21% of new breast cancers were diagnosed as a resul t of a screening program visit. Interpretation: Substantial increases in health care expenditures have been avoided; by shifting bilateral mammography services to the provincial scre ening program, which ha's a lower cost per screening visit.