Digital mammography may not be cost effective
Digital mammography may only be more cost effective than film mammography for women who are under age 50, premenopausal or who have dense breasts, according to a new study published in the Jan. 1 issue of the Annals of Internal Medicine.

The researchers decided to assess its cost-effectiveness because the Digital Mammography Imaging Screening Trial (DMIST) reported improved breast cancer detection with digital mammography compared to film mammography in selected population subgroups. Yet, the researchers observed that it did not assess the economic value of digital relative to film mammography screening. DMIST, an ACR imaging network trial including more than 49,500 women in the United States and Canada, was initially published in November 2005 by the New England Journal of Medicine.

Anna N.A. Tosteson, ScD, from Dartmouth Medical School in Lebanon, N.H., and colleagues targeted U.S. women who were 40 years or older for the study, and used data from DMIST and publicly available U.S. data. The researchers evaluated the cost per quality-adjusted life-year (QALY) gained.

The authors found that all-digital mammography screening cost approximately $331,000 ($268,000 to $403,000) per QALY gained relative to all-film mammography screening but was more costly and less effective than targeted digital mammography screening. Targeted digital mammography screening resulted in more screen-detected cases of cancer and fewer deaths from cancer than either all-film or all-digital mammography screening, with cost-effectiveness estimates ranging from $26,500 ($21,000 to $33,000) per QALY gained for age-targeted digital mammography to $84,500 ($75,000 to $93 000) per QALY gained for age- and density-targeted digital mammography, according to the researchers.

In the Medicare population, the authors found that the cost-effectiveness of density-targeted digital mammography screening varied from a base-case estimate of $97,000 ($77,000 to $131 000) to $257,000 per QALY gained ($91,000 to $536,000) in the alternative-case analyses, in which the sensitivity of film mammography was increased and the sensitivity of digital mammography in women with non-dense breasts was decreased.

Currently, Medicare reimburses $50 more per examination for digital than for film mammography.

The researchers concluded that relative to film mammography, screening for breast cancer by using all-digital mammography is not cost-effective. Age-targeted screening with digital mammography seems cost-effective, whereas density-targeted screening strategies are more costly and of uncertain value, particularly among women age 65 years or older, the authors wrote.

The researchers said that their findings imply that the cost-effectiveness of digital mammography varies substantially, depending on whether and how its use is targeted.

The researchers hailed from Dartmouth Institute for Health Policy and Clinical Practice at Dartmouth Medical School in Lebanon, N.H.; Harvard School of Public Health in Boston; University of Wisconsin in Madison, Wis.; Brown University in Providence, R.I.; and University of North Carolina at Chapel Hill in N.C. The study was funded by the National Cancer Institute.