Research Brief: Screening Mammography Rates in the Medicare Population Before and After the 2009 U.S. Preventive Services Task Force Guideline Change

This study explores how the 2009 guidelines on screening mammography released by the US Preventive Services Task Force (USPSTF) may have affected screening mammography rates among women aged 65 and older. The guidelines outlined in the figure below recommended against routine screening for women aged 40-49 years (unless warranted by individual patient context and values); screening every 2 years for women aged 50-74 years; and had no recommendation for women aged 75 and older due to a lack of evidence of benefit for this age group. The guideline change prompted considerable debate and investigation, but the impact of the change on actual screening rates was unclear.

USPSTF Guidelines ChartUsing data from Medicare fee-for-service claims for a 5 percent random sample of beneficiaries for the period 2005 through 2012, Miao Jiang and colleagues found that prior to the guideline change rates of screening mammography had been increasing for all Medicare beneficiaries ages 65 to 90. After the release of the new guidelines there was an immediate and significant — though short-term — decrease in screening of 1.76 per 1,000 women for all groups studied. Three years later after the initial decline, the screening rate stabilized for women aged 65 to 74 and continued to decline for those aged 75 and older.

Background and Implications

A prior study by Jiang using private insurance claims showed a decrease in screening for women aged 40 to 64 before the guideline change. But after the change in guidelines, there was a surprising increase in usage for women in the 40 to 49 age group. Those findings in younger patients were the opposite of what the researchers observed in the Medicare population. The authors attributed this trend “to intense media coverage and the national economic recovery, but did not discuss possible insurance coverage changes as a potential contributing factor.” For the medicare population the scenario is different. Annual mammography screening is fully covered. Since randomized trials evaluating screening mammography did not include women over age 74 (and there is a lack of evidence of benefit for this age group as the USPSTF indicated), it appears that that particular age group is following their guidelines.

Since 2009, the debate about screening mammography has continued. Randomized controlled trials of hundreds of thousands of women over long periods of time had already found that compared to women in the unscreened group, there was a 15 percent reduction in the number of deaths from breast cancer in the screened group, and no reduction in deaths overall. Yet a large Canadian study with 25 years of follow-up put that screening-associated reduction at zero. There is now a greater focus on judging the harms of overdiagnosis and overtreatment due to routine screening and the limitations of screening to reduce all-cause mortality. It appears that for every woman whose life is spared from a breast cancer death, another dies from the downstream interventions induced by screening.

Recent changes in guidelines from the American Cancer Society (ACS) muddy the waters further. In an attempt to balance the potential benefits and harms of screening, the ACS now recommends that women of average risk undergo regular screening mammography starting at age 45 years (strong recommendation). Women aged 45 to 54 years should be screened annually (qualified recommendation). Women 55 years and older should transition to biennial screening or have the opportunity to continue screening annually (qualified recommendation). Women should have the opportunity to begin annual screening between ages 40 and 44 (qualified recommendation). Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer (qualified recommendation). The ACS does not recommend clinical breast examination for breast cancer screening among average-risk women at any age (qualified recommendation). These guidelines move closer to those from the USPSTF, but do not correspond entirely.

The research by Miao Jiang and colleagues strongly suggest: “Behavioral changes should be anticipated when professional organizations issue competing guidelines; their important public policy implications may impact distinct demographic groups differently, and their results may not be fully quantifiable for many years after their implementation.”

Source: Miao Jiang, Danny R. Hughes, and Richard Duszak Jr. “Screening Mammography Rates in the Medicare Population before and after the 2009 U.S. Preventive Services Task Force Guideline Change: An Interrupted Time Series Analysis.” Women’s Health Issues, Vol. 25, Iss. 3 (May/June 2015), pp: 239–245. Download here (PDF).
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