San Francisco, CA—Within weeks of a government-backed recommendation against routine screening mammography in women aged <50 years, the screening rate had fallen below historic levels and subsequently has remained lower than the baseline rate, a group of researchers reported.
Two months after the US Preventive Services Task Force (USPSTF) recommendation, the screening rate among women aged 40 to 49 years was almost 8% lower compared with rates before the 2009 decision. Two years later, the screening rate among younger women was still 5% lower than during the period from January 2006 to October 2009.
“More than 90,000 fewer mammograms were performed in women aged 40 to 49 in the 2 years after the USPSTF update,” Amy T. Wang, MD, Assistant Professor of Medicine, College of Medicine, Mayo Clinic, Rochester, MN, and colleagues reported in a poster presentation at the 2012 Breast Cancer Symposium.
The screening rate did not change in women aged 50 to 64 years, for whom the USPSTF recommended a 2-year screening interval instead of an annually.
“The results are consistent with the context of the update,” the researchers added. There was no difference in the 50-to-64 age-group, consistent with a more subtle change (biennial vs annual mammography). The modest decrease in the 40-to-49 age-group is consistent with a more radical change (ie, against routine mammography vs for it).
The results also are consistent with public resistance to the guideline change and the subsequent release of conflicting guidelines, Dr Wang and colleagues concluded.
The 2009 USPSTF recommendations ignited a controversy that continues to play out almost 3 years later. For the most part, the controversy has centered on the recommendation against routine screening mammography for younger women. By comparison, the change to a 2-year screening interval for women aged 50 to 64 years has evoked little comment.
The American Cancer Society, the American College of Radiology, and several other professional and consumer advocacy groups assailed the recommendation for women aged <50 years. The American College of Obstetricians and Gynecologists issued updated and new screening guidelines that make no age-based distinctions in screening frequency.
Dr Wang and colleagues performed the first reported study to evaluate the impact of the USPSTF recommendations on screening rates in different age-groups. Analyzing administrative data from more than 100 health plans, the researchers included 11.4 million women in the study.
For the baseline period of January 2006 to October 2009, the rate of screening mammography was 39.3 per 1000 women aged 40 to 49 years and 47.0 per 1000 women aged 50 to 64 years. Two months after the USPSTF released the updated recommendations, the screening rate had decreased by 7.59% among women aged 40 to 49 years. A year after the update, the screening rate in the younger group remained 5.33% less than historic rates, and 2 years later, the screening rate in women aged 40 to 49 years remained 5.02% below baseline.
The mammography rate among women aged 50 to 64 years showed little variation from baseline after the release of the USPSTF update.
The results show that the USPSTF decision has affected care and clinical decision-making related to screening mammography, said invited discussant Thomas Buchholz, MD, Professor and Division Head, Department of Radiation Oncology, The University of Texas M.D. Anderson Cancer Center in Houston. The recommendations have influenced individual patients’ choices, doctors’ recommendations, and third-party decisions regarding coverage of mammography.
