State Medicaid expansion status, insurance coverage and stage at diagnosis in head and neck cancer patients

Only one in three head and neck cancer (HNC) patients present with early-stage disease. We aimed to quantify associations between state Medicaid expansions and changes in insurance coverage rates and stage at diagnosis of HNC.

Using a quasi-experimental difference-in-differences (DID) approach and data from 26,330 cases included in the Surveillance, Epidemiology, and End Results program (2011-2015), we retrospectively examined changes in insurance coverage and stage at diagnosis of adult HNC in states that expanded Medicaid (EXP) versus those that did not (NEXP).

There was a significant increase in Medicaid coverage in EXP (+1.6 percentage point (PP) versus) vs. NEXP (-1.8 PP) states (3.36 PP, 95% CI = 1.32, 5.41; p = 0.001), and this increase was mostly among residents of low income and education counties. We also observed a reduction in uninsured rates among HNC patients in low income counties (-4.17 PP, 95% CI = -6.84, -1.51; p = 0.002). Overall, early stage diagnosis rates were 28.3% (EXP) vs. 26.7% (NEXP), with significant increases in early stage diagnosis post-Medicaid expansion among young adults, 18-34 years (17.2 PP, 95% CI - 1.34 to 33.1, p = 0.034), females (7.54 PP, 95% CI = 2.00 to 13.10, p = 0.008), unmarried patients (3.83 PP, 95% CI = 0.30-7.35, p = 0.033), and patients with lip cancer (13.5 PP, 95% CI = 2.67-24.3, p = 0.015).

Medicaid expansion is associated with improved insurance coverage rates for HNC patients, particularly those with low income, and increases in early stage diagnoses for young adults and women.