Impact of medicaid expansion on cervical cancer screening: A state-specific difference in difference analysis

In 2014 the Affordable Care Act expanded Medicaid coverage in states that opted to participate. Limited data are available describing the effect of Medicaid expansion on cancer screening. The objective of our study was to evaluate trends in cervical cancer screening associated with Medicaid expansion.

Using data from the Behavioral Risk Factor Surveillance System, we identified female respondents ages 30-64 years with a household income below $35,000. The outcome measure was guideline-adherent cervical cancer screening. The years 2010 and 2012 constituted the pre-expansion period while 2016 and 2018 were used to capture the post-expansion period. A difference-in-difference (DID) analysis was performed to assess changes in cervical cancer screening in Medicaid expansion states compared to non-expansion states, for the overall sample and for each expansion state individually.

The overall DID analysis showed a greater increase in cervical cancer screening by 1.1 percentage points (95% CI: 0.1 to 2.0%, P = 0.03) in expansion states compared to non-expansion states. The analysis comparing individual expansion states to non-expansion states showed that 6 expansion states had a significantly higher increase in screening relative to non-expansion states: Oregon (8.5%, P < 0.001), Kentucky (4.5%, P = 0.001), Washington (4.2%, P = 0.002), Colorado (4.3%, P = 0.008), Nevada (4.7%, P = 0.048), and Ohio (2.8%, P = 0.03). Of these states, 5 ranked among the states with the lowest baseline screening rates.

Medicaid expansion states experienced a greater increase in cervical cancer screening relative to non-expansion states. Expansion states with lower baseline screening rates experienced greater increases in screening after expanding Medicaid.