5 Background: The 11/2009 USPSTF breast cancer screening update recommended against routine screening mammography for women age 40-49, created confusion and prompted organizations to release opposing statements. We aimed to determine if the USPSTF update for breast cancer screening impacted screening mammography utilization in women age 40-49. Methods: We conducted a time-series analysis utilizing administrative claims data from over 100 health plans. Women ages 40-64 with at least one month of enrollment from 01/2006-12/2010 were included. Medicare claims are not included and thus women ≥65 were excluded. The start date of 01/2006 was chosen to account for possible effects of the recent recession. We developed claims-based algorithms to identify the number of monthly screening mammograms. Time series models were fit using SAS PROC AUTOREG; strong seasonal fluctuations were adjusted by including an autoregressive error of order 12. Results: Over 7.9 million women were included. Prior to the intervention, the baseline monthly mammography rate was 40.9/1,000 women for the 40-49 group and 47.4/1,000 women for the 50-64 group. Based on projections from pre-intervention trends, the update was associated with a 5.72% (1.27,10.18) and 4.97% (1.11,8.84) decrease in mammography rate at 3 and 10 months post-intervention, respectively in the 40-49 group. The intervention had no effect on mammography rates in the 50-64 group. This translates to 53,969 fewer mammograms performed in the year following the update for women ages 40-49 in this dataset. Conclusions: We present the first estimates of the impact of the USPSTF breast cancer screening update using a large nationally representative database. The update was associated with a small but significant decrease in mammography rates for women ages 40-49, while no change was seen for women ages 50-64, which is consistent with the context of the guideline change. A modest effect is also in line with public backlash and the release of numerous conflicting guidelines. These findings underscore the need for further research on benefits and risks of screening mammography as it is difficult to act on numerous sources of contradictory information.
The impact of false positive breast cancer screening mammograms on screening retention: A retrospective population cohort study in Alberta, Canada