Impact of Medicaid expansion on post-mastectomy breast reconstruction.

206 Background: Disparities in post-mastectomy reconstruction exist by income and insurance type. The Affordable Care Act introduced Medicaid expansion as a key strategy to improve healthcare access for low-income Americans. The objective was to examine the impact of Medicaid expansion on receipt of post-mastectomy reconstruction. Methods: We identified women aged <65 with stage 0-3 breast cancer treated with mastectomy (2009-2022), using the National Cancer Database. Exclusion criteria included radiation, early/late Medicaid expansion states, and Medicare/government or unknown insurance. Multivariable logistic regression models assessed whether the odds of reconstruction differed in Medicaid expansion vs non-expansion states, before and after 1/2014 (difference in difference analysis). A three-way interaction assessed how differences in odds of reconstruction between expansion and non-expansion states differed over time based on insurance type. Adjusted average predicted probabilities of reconstruction were generated. Results: Relative to the pre-expansion period, women in expansion states after 2014 had 16% lower odds of reconstruction compared to those in non-expansion states, (OR 0.84; 95% CI 0.81-0.87). There was not a statistically significant three-way interaction between Medicaid expansion, time, and insurance type. Data demonstrated a decline in the predicted probability of reconstruction among privately insured patients pre- and post-2014, in both expansion and non-expansion states (Table). Modest increases in reconstruction for Medicaid and uninsured patients were observed before and after 2014, with greater increases in non-expansion states. Conclusions: We did not observe an increase in rates of reconstruction for women treated in Medicaid expansion states over time. This suggests that access to insurance coverage alone is not enough to support disadvantaged patients undergoing reconstruction. Given that reconstruction requires larger and often multiple procedures, the decision is likely influenced by other factors (e.g. work leave, caregiving needs, cost of travel) that disproportionately impact disadvantaged patients and may impact their motivation for reconstruction. Adjusted average predicted probabilities of reconstruction rates by state Medicaid expansion status, pre and post 2014.* Non-Expansion States Expansion States 2009-2013 n=52,199 2014-2022 n=102,149 2009-2013 n=40,172 2014-2022 n=76,197 Overall n=270,717 51.8% (51.4-52.3) 52.0% (51.6-52.4) 52.2% (51.6-52.7) 48.2% (47.7-48.6) Insurance Type Private n=239,009 55.%0 (54.5-55.5) 53.6% (53.3-54.0) 54.6% (54.0-55.2) 49.8% (49.3-50.2) Medicaid n=24,327 29.6% (28.1-31.1) 37.9% (36.7-39.2) 35.4% (33.7-37.0) 38.8% (37.7-39.7) Uninsured n=7,381 25.4% (23.5-27.4) 34.6% (32.8-36.4) 28.3% (25.1-31.6) 32.9% (29.5-36.3) *Adjusted for age, region, census-based median income, Charlson comorbidity index.