Tuesday, 1 January 2008

Cost-Effectiveness of Digital Mammography Breast Cancer Screening

A paper in the Annals of Internal Medicine published today 1 January 2008, Volume 148 Issue 1, Pages 1-10, was part of the economic analysis of implementing the move to digital mammography as part of the ACRIN 6652 DMIST study, which reported in October 2006.

The authors Dr. Anna Tosteson et al, from Dartmouth Medical School, performed a discrete event-simulation model to evaluate the cost effectiveness of Digital Mammography (FFDM) compared with analogue (film-screen) mammography. The headline result shows that there are NO cost savings by moving to digital unless breast screening is targeted to a higher risk population where digital mammography has been proven to have a better track record for detecting cancer like younger women with dense breasts.

While this study is useful as it relates to QALYs and cost per life year saved, there are other real world events that also have to be taken into consideration when deciding whether to upgrade your mammography machine to digital.

One of these factors is the decreasing production of medical x-ray film and chemicals, which will eventually be phased out. There are other benefits of moving to digital, which include the eventual elimination of film libraries, physical film hanging, along with the elimination of having to deal with dangerous chemicals and the environmental aspects of disposal of the used developer and fixer. Photographic emulsions are steadily being phased out, so in the medium to long term, there is no real question that digital mammography has to be the final solution.

Perhaps we were originally aiming too high in the original trials, as scientifically it is correct that there has to be a benefit compared with the gold standard examination. An economic evaluation was correctly performed but maybe the most important finding is that digital mammography in its 2003-4 iteration was as good as, and occasionally more accurate than conventional mammography.

Pragmatically, when replacing a mammography unit, a digital one should be purchased. Newer versions of FFDM are better quality, and can only improve our ability to diagnose breast cancer. Workstations and comparison with prior mammograms are now the current challenges facing us as we move forward in attempting to advance the diagnosis of breast cancer.