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

Abstract

Objective: We sought to examine longitudinal trends in screening mammography utilization and the presence of any changes in utilization associated with the 2009 U.S. Preventive Services Task Force (USPSTF) guideline change.

Methods: We use 2005 through 2012 Medicare fee-for-service claims data for a 5% sample of randomly selected beneficiaries. The primary outcome is monthly mammography rate per 1,000 women. Two comparison outcomes are monthly Papanicolaou test rate and monthly routine eye examination rate. The statistical approach is interrupted time series with segmented regression analysis and nonequivalent dependent variables.

Results: Among women age 65 and 90, monthly screening mammography rates were significantly increasing before the 2009 USPSTF guideline change. Immediately after the guidelines, there was a significant drop of 1.76 per 1,000 women (p < .001). Three years after the guideline, and after the initial decrease, there was no significant change in rate for those aged 65 to 74, but a continued and significant decline for those aged 75 and older. Two other preventive services (Papanicolaou test and routine eye examinations) did not show any shift associated with the pre- and post-guideline window.

Conclusions: The 2009 revision of USPSTF guidelines on breast cancer was associated with an immediate and significant decrease in screening mammography rates. The long-term impact of the guideline change differs by age and race and may not be fully quantifiable for years after its implementation.