Background

The Affordable Care Act expanded Medicaid coverage for people with low income in the United States. Expanded insurance coverage could promote more timely access to cancer treatment, which could improve overall survival (OS), yet the long-term effects of Medicaid expansion (ME) remain unknown. We evaluated whether ME was associated with improved timely treatment initiation (TTI) and 3-year OS among patients with breast, cervical, colon, and lung cancers who were affected by the policy.

Methods

Medicaid-insured or uninsured patients aged 40-64 with stage I-III breast, cervical, colon, or non-small cell lung cancer within the National Cancer Database (NCDB). A difference-in-differences (DID) approach was used to compare changes in TTI (within 60 days) and 3-year OS between patients in ME states versus nonexpansion (NE) states before (2010-2013) and after (2015-2018) ME. Adjusted DID estimates for TTI and 3-year OS were calculated using multivariable linear regression and Cox proportional hazards regression models, respectively.

Results

ME was associated with a relative increase in TTI within 60 days for breast (DID = 4.6; p < 0.001), cervical (DID = 5.0 p = 0.013), and colon (DID = 4.0, p = 0.008), but not lung cancer (p = 0.505). In Cox regression analysis, ME was associated with improved 3-year OS for breast (DID hazard ratio [HR] = 0.82, p = 0.009), cervical (DID-HR = 0.81, p = 0.048), and lung (DID-HR = 0.87, p = 0.003). Changes in 3-year OS for colon cancer were not statistically different between ME and NE states (DID-HR, 0.77; p = 0.075).

Conclusions

Findings suggest that expanded insurance coverage can improve treatment and survival outcomes among low income and uninsured patients with cancer. As the debate surrounding ME continues nationwide, our findings serve as valuable insights to inform the development of policies aimed at fostering accessible and affordable healthcare for all.