Recent trends in adherence to continuous screening for breast cancer among Medicare beneficiaries

Abstract

Objective: The aim of this study is to examine recent trends in adherence to continuous screening, especially the rate of subsequent screening mammography following an initial screening before and after the U.S. Preventive Services Task Force (USPSTF) revised its guidelines on breast cancer in November 2009.

Methods: We retrospectively analyzed Medicare fee-for-service claims data to: 1) compare rate of subsequent screening mammography over 27 month periods for 317,150 women screened in either 2004 or 2009; and 2) examine patterns of subsequent screening by age and race.

Results: When adjusted for age, race, state of residence, county-level covariates, and clustered on ordering provider, the rate of subsequent screening decreased in 2009 relative to 2004 (OR=0.75; 95% CI: 0.74-0.76). Adjusted odds ratios are similar for alternative follow-up windows (15 months, 0.71; 24 months, 0.70; 30 months 0.75). The decline was mostly attributable to women 75 and older who are now less likely to return for a subsequent screening. Although USPSTF guidelines call for 24 months, approximately half of women continue screening at 12-month intervals in both cohorts.

Conclusions: The rate of subsequent screening mammography has declined after 2009. Older women seem to follow the revised USPSTF guideline, but confusion by physicians and patients about competing guidelines may be contributing to these findings.

Keywords: Adherence; Mammography; Medicare; Screening; USPSTF (U.S. Preventive Services Task Force).