Potential overuse of screening mammography and its association with access to primary care

Cancer screening in individuals with limited life expectancy increases the risk of diagnosis and treatment of cancer that otherwise would not have become clinically apparent.

To estimate screening mammography use in women with limited life expectancy, its geographic variation, and association with access to primary care and mammographic resources.

We assessed screening mammography use in 2008-2009 in 106,737 women aged 66 years or older with an estimated life expectancy of <7 years using a 5% national sample of Medicare beneficiaries. Descriptive statistics were used to estimate the screening mammography utilization, by access to primary care.

Among women with a life expectancy of <7 years, 28.5% received screening mammography during 2008-2009. The screening rates were 34.6% versus 20.5% for women with and without an identifiable primary care physician, respectively. The screening rates were higher among women who saw >1 generalist physician and who had more visits to generalist physicians. There was substantial geographic variation across the United States, with an average rate of 39.5% in the hospital referral regions (HRRs) in the top decile of screening versus 19.5% in the HRRs in the bottom decile. The screening rates were higher among HRRs with more primary care physicians (r=0.14, P=0.02), mammography facilities (r=0.12, P=0.04), and radiologists (r=0.22, P<0.001).

Substantial proportions of women with limited life expectancy receive screening mammography. Results presented sound a cautionary note that greater access to primary care and mammographic resources is also associated with higher overuse.