{Reference Type}: Journal Article
{Title}: Medicaid expansion in California and breast cancer incidence across neighborhoods with varying social vulnerabilities.
{Author}: Li L;Yang C;Huang Y;Zhan S;Hu L;Zou J;Yu M;Mazumdar M;Liu B;
{Journal}: Cancer Causes Control
{Volume}: 0
{Issue}: 0
{Year}: 2024 Jun 14
{Factor}: 2.532
{DOI}: 10.1007/s10552-024-01893-1
{Abstract}: <B>OBJECTIVE: </B>To investigate changes in breast cancer incidence rates associated with Medicaid expansion in California.<BR><B>METHODS: </B>We extracted yearly census tract-level population counts and cases of breast cancer diagnosed among women aged between 20 and 64 years in California during years 2010-2017. Census tracts were classified into low, medium and high groups according to their social vulnerability index (SVI). Using a difference-in-difference (DID) approach with Poisson regression models, we estimated the incidence rate, incidence rate ratio (IRR) during the pre- (2010-2013) and post-expansion periods (2014-2017), and the relative IRR (DID estimates) across three groups of neighborhoods.<BR><B>RESULTS: </B>Prior to the Medicaid expansion, the overall incidence rate was 93.61, 122.03, and 151.12 cases per 100,000 persons among tracts with high, medium, and low-SVI, respectively; and was 96.49, 122.07, and 151.66 cases per 100,000 persons during the post-expansion period, respectively. The IRR between high and low vulnerability neighborhoods was 0.62 and 0.64 in the pre- and post-expansion period, respectively, and the relative IRR was 1.03 (95% CI 1.00 to 1.06, p = 0.026). In addition, significant DID estimate was only found for localized breast cancer (relative IRR = 1.05; 95% CI, 1.01 to 1.09, p = 0.049) between high and low-SVI neighborhoods, not for regional and distant cancer stage.<BR><B>CONCLUSIONS: </B>The Medicaid expansion had differential impact on breast cancer incidence across neighborhoods in California, with the most pronounced increase found for localized cancer stage in high-SVI neighborhoods. Significant pre-post change was only found for localized breast cancer between high and low-SVI neighborhoods.