Association of the Affordable Care Act with access to highest-volume centers for patients with thyroid cancer

Disparities exist in access to high-volume surgeons, who have better outcomes after thyroidectomy. The association of the Affordable Care Act’s Medicaid expansion with access to high-volume thyroid cancer surgery centers remains unclear. The National Cancer Database was queried for all adult thyroid cancer patients diagnosed from 2010 to 2016. Hospital quartiles (Q1–4) defined by operative volume were generated. Clinicodemographics and adjusted odds ratios for treatment per quartile were analyzed by insurance status. An adjusted difference-in-differences analysis examined the association between implementation of the Affordable Care Act and changes in payer mix by hospital quartile. In total, 241,448 patients were included. Medicaid patients were most commonly treated at Q3–Q4 hospitals (Q3 odds ratios 1.05, P = .020, Q4 1.11, P < .001), whereas uninsured patients were most often treated at Q2–Q4 hospitals (Q2 odds ratios 2.82, Q3 2.34, Q4 2.07, P < .001). After expansion, Medicaid patients had lower odds of surgery at Q3–Q4 compared with Q1 hospitals (odds ratios Q3 0.82, P < .001 Q4 0.85, P = .002) in expansion states, but higher odds of treatment at Q3–Q4 hospitals in nonexpansion states (odds ratios Q3 2.23, Q4 1.86, P < .001). Affordable Care Act implementation was associated with increased proportions of Medicaid patients within each quartile in expansion compared with nonexpansion states (Q1 adjusted difference-in-differences 5.36%, Q2 5.29%, Q3 3.68%, Q4 3.26%, P < .001), and a decrease in uninsured patients treated at Q4 hospitals (adjusted difference-in-differences –1.06%, P = .001). Medicaid expansion was associated with an increased proportion of Medicaid patients undergoing thyroidectomy for thyroid cancer in all quartiles, with increased Medicaid access to high-volume centers in expansion compared with nonexpansion states.