Association Between Medicaid Expansion and Diagnosis and Management of Colon Cancer

The Affordable Care Act facilitated improved insurance coverage for states that expanded Medicaid coverage, but the impact on cancer outcomes is unclear. This study compared changes in the diagnosis and management of colon cancer in states that did and did not participate in Medicaid expansion.

Using a quasi-experimental difference-in-differences (DID) approach, we analyzed Medicaid and uninsured patients in the National Cancer Data Base during 2 time periods: pre (2011-2012) and post expansion (2015-2016). Patients in non-expansion states were compared with those in January 2014 expansion states with regard to changes in patient and facility characteristics, cancer staging, treatment decisions, and surgical outcomes.

Along with increased Medicaid coverage (DID = 20.27; p < 0.001), patients in expansion states had an increase in stage I diagnoses (DID = 2.97; p = 0.035), distance traveled (miles, DID = 6.67; p = 0.005), and treatment at integrated network programs (DID = 2.67; p = 0.045). More early-stage patients were treated within 30 days (DID = 7.24; p = 0.035) and more stage IV patients received palliative care (DID = 5.01; p = 0.048). Among surgical patients, Medicaid expansion correlated with fewer urgent cases (< 7 days, DID = -5.88; p = 0.008) and more minimally invasive surgery (DID = 5.00; p = 0.022). There were no observed differences in postoperative outcomes or adjuvant chemotherapy.

Medicaid expansion correlated with earlier diagnosis, enhanced access, and improved surgical care for colon cancer patients. These findings highlight the importance of improving health insurance coverage and can help guide future policy efforts.