Screening Mammography for Free: Impact of Eliminating Cost Sharing on Cancer Screening Rates

To study the impact of eliminating cost sharing for screening mammography on mammography rates in a large Medicare Advantage (MA) health plan which in 2010 eliminated cost sharing in anticipation of the Affordable Care Act mandate.

Large MA health maintenance organization offering individual-subscriber MA insurance and employer-supplemented group MA insurance.

We investigated the impact on breast cancer screening of a policy that eliminated a $20 copayment for screening mammography in 2010 among 53,188 women continuously enrolled from 2007 to 2012 in an individual-subscriber MA plan, compared with 42,473 women with employer-supplemented group MA insurance in the same health maintenance organization who had full screening coverage during this period. We used differences-in-differences analysis to study the impact of cost-sharing elimination on mammography rates.

Annual screening rates declined over time for both groups, with similar trends pre-2010 and a slower decline after 2010 among women whose copayments were eliminated. Among women aged 65-74 years in the individual-subscriber MA plan, 44.9 percent received screening in 2009 compared with 40.9 percent in 2012, while 49.5 percent of women in the employer-supplemented MA plan received screening in 2009 compared with 44.1 percent in 2012, that is, a difference-in-difference effect of 1.4 percentage points less decline in screening among women experiencing the cost-sharing elimination. Effects were concentrated among women without recent screening. There were no differences by neighborhood socioeconomic status or race/ethnicity.

Eliminating cost sharing for screening mammography was associated with modesty lower decline in screening rates among women with previously low screening adherence.