Breast cancer screening guidelines recommend that women and physicians consider life expectancy when making screening decisions in older women. However, prior studies suggest that screening mammography patterns are dependent on age rather than health status or mortality risk of women. Our objective is to determine the association between 4-year mortality risk and use of screening mammography in women aged ≥ 65 years using Medicare Current Beneficiary Survey data.
The primary predictor variable is 4-year mortality risk derived from a published and validated prognostic index with 4 strata of increasing probability of death in 4 years (risk groups 1, 2, 3, and 4 with 4%, 15%, 42%, and 64% risk of 4-year mortality, respectively). The main outcome was self-reported receipt of mammography in the last year.
There was a significant decreasing trend in the use of mammography with mortality risk groups 1, 2, 3, and 4 (62.7%, 51.5%, 36.6%, and 24%, respectively; trend test P<.001). The adjusted odds of mammography use were greatest in the low mortality risk group and show a gradual decline with increasing mortality risk for risk groups 1, 2, 3, and 4 (odds ratio [confidence interval]): 1.00; 0.69 [0.53-0.90]; 0.37 [0.27-0.49], and 0.22 [0.13-0.36], respectively.
Screening mammography use in older Medicare beneficiaries seems to reflect their 4-year risk of mortality rather than age alone, suggesting that patients and providers consider prognosis in screening decisions. Prospective studies are needed to explore the use of the prognostic index as a mammography screening decision tool.