ACA Medicaid expansion reduced disparities in use of high-volume hospitals for pancreatic surgery.

Background: Early evaluation of the Affordable Care Act's Medicaid expansion demonstrated persistent disparities among Medicaid beneficiaries in use of high-volume hospitals for pancreatic surgery. Longer-term effects of expansion remain unknown. This study evaluated the impact of expansion on the use of high-volume hospitals for pancreatic surgery among Medicaid and uninsured patients.

Methods: State inpatient databases (2012-2017), the American Hospital Association Annual Survey Database, and the Area Resource File from the Health Resources and Services Administration, were used to examine 8,264 non-elderly adults who underwent pancreatic surgery in nine expansion and two non-expansion states. High-volume hospitals were defined as performing 20 or more resections/year. Linear probability triple differences models measured pre- and post-Affordable Care Act utilization rates of pancreatic surgery at high-volume hospitals among Medicaid and uninsured patients versus privately insured patients in expansion versus non-expansion states.

Results: The Affordable Care Act's expansion was associated with increased rates of utilization of high-volume hospitals for pancreatic surgery by Medicaid and uninsured patients (48% vs 55.4%, P = .047) relative to privately insured patients in expansion states (triple difference estimate +11.7%, P = .022). A pre-Affordable Care Act gap in use of high-volume hospitals among Medicaid and uninsured patients in expansion states versus non-expansion states (48% vs 77%, P < .0001) was reduced by 15.1% (P = .001) post Affordable Care Act. A pre Affordable Care Act gap between expansion versus non-expansion states was larger for Medicaid and uninsured patients relative to privately insured patients by 24.9% (P < .0001) and was reduced by 11.7% (P = .022) post Affordable Care Act. Rates among privately insured patients remained unchanged.

Conclusion: Medicaid expansion was associated with greater utilization of high-volume hospitals for pancreatic surgery among Medicaid and uninsured patients. These findings are informative to non-expansion states considering expansion. Future studies should target understanding referral mechanism post-expansion.