In a comparative modeling study, conducted by the Harvard Pilgrim Health Care Institute and National Cancer Institute -sponsored consortia, researchers used five independent breast cancer simulation models, developed through the Cancer Intervention and Surveillance Modeling Network, to examine the health benefits and harms as well as economic costs of screening strategies using digital mammography. In addition to examining the impact of using digital instead of film for routine screening, researchers also examined digital screening strategies starting at age 40 or 50 applied annually, biennially, or based on mammographic breast density. Mammography performance and information on breast density were based on data from the Breast Cancer Surveillance Consortium. Model outcomes included mortality reductions, life expectancy, quality-adjusted life expectancy and costs. Incremental cost-effectiveness ratios comparing strategies were computed.
Results demonstrated that routine use of digital mammography modestly improved health relative to film mammography, but resulted in increased overall cost largely due to higher reimbursement for digital and more false positive workups.
According to researcher and first author Natasha Stout, PhD of the Department of Population Medicine at Harvard Pilgrim Health Care Institute and Harvard Medical School, the impact of these unintended consequences on population health and medical costs should be evaluated before widespread adoption of any new technology.
The researchers also found that a policy to extend biennial screening with digital mammography to women 40-49 years could be a reasonable value especially for women who are not adversely affected by the prospect of a false positive test. Across the 5 models, extending biennial digital screening to women ages 40-49 relative to screening women 50-74 would lead to a median gain of 5 days in life expectancy, avert 1.1 additional deaths per 1000 women screened and increase costs by $0.69 million. However, when quality of life effects such as anxiety from screening and possible false positive results or invasive diagnostic workups are considered for women in their 40s, the small gain in health is reduced and this policy is less attractive from a cost-effectiveness perspective. Screening annually from ages 40-74 resulted in the greatest health gains but also markedly higher costs and false positives than biennially screening.