Registry-based study of trends in breast cancer screening mammography before and after the 2009 U.S. Preventive Services Task Force recommendations

Abstract

Purpose: To determine whether the 2009 U.S. Preventive Services Task Force (USPSTF) guidelines for breast cancer mammography screening were followed by changes in screening utilization in the state of Vermont.

Materials and methods: This retrospective study was HIPAA compliant and approved by the institutional review board, with waiver of informed consent. Trends in screening mammography utilization during 1997-2011 were examined among approximately 150,000 women aged 40 years and older in the state of Vermont using statewide mammography registry data.

Results: The percentage of Vermont women aged 40 years and older screened in the past year declined from 45.3% in 2009% to 41.6% in 2011 (an absolute decrease of -3.7 percentage points; 95% confidence interval [CI]: -3.3, -4.1). The largest decline in utilization was among women aged 40-49 years (-4.8 percentage points; 95% CI: -4.1, -5.4), although substantial declines were also observed among women aged 50-74 years (-3.0 percentage points; 95% CI: -2.6, -3.5) and women aged 75 years and older (-3.1 percentage points; 95% CI: -2.3, -4.0). The percentage of women aged 50-74 years screened within the past 2 years declined by -3.4 percentage points (95% CI: -3.0, -3.9) from 65.4% in 2009 to 61.9% in 2011.

Conclusion: After years of increasing screening mammography utilization in Vermont, there was a decline in screening, which coincided with the release of the 2009 USPSTF recommendations. The age-specific patterns in utilization were generally consistent with the USPSTF recommendations, although there was also evidence that the percentage of women aged 50-74 years screened in the past 2 years declined since 2009.

Figure 1:

Observed trends in the age-adjusted percentage of Vermont women aged 40 years and older who underwent screening mammography in the past year and past 2 years. Solid lines depict the best fits from the join-point analyses.

Figure 2a:

Observed trends in the percentage of Vermont women who underwent screening mammography (a) in the past year and (b) past 2 years according to age group. Solid lines depict the best fits from the join-point analyses.

Figure 2b:

Observed trends in the percentage of Vermont women who underwent screening mammography (a) in the past year and (b) past 2 years according to age group. Solid lines depict the best fits from the join-point analyses.

Figure 3a:

Utilization of screening mammography in Vermont according to screening interval. (a) Observed age-adjusted percentage of Vermont women aged 40 years and older who underwent mammography according to the time since their last mammography examination (annual, ≤ 18 months; biennial, 19–30 months; longer, > 30 months). (b) Observed percentage of Vermont women who underwent annual screening mammography (≤ 18 months since a previous mammography examination) according to age group. Solid lines depict the best fits from the join-point analyses.

Figure 3b:

Utilization of screening mammography in Vermont according to screening interval. (a) Observed age-adjusted percentage of Vermont women aged 40 years and older who underwent mammography according to the time since their last mammography examination (annual, ≤ 18 months; biennial, 19–30 months; longer, > 30 months). (b) Observed percentage of Vermont women who underwent annual screening mammography (≤ 18 months since a previous mammography examination) according to age group. Solid lines depict the best fits from the join-point analyses.