2025 Poster Presentations
P148: THE IMPACT OF MEDICAID EXPANSION ON INTRACRANIAL MENINGIOMA INCIDENCE
Ryan Armijo, BA1; Alexander Homer, BA2; Carl Heilman, MD3; Kathryn Noonan, MD4; 1Tufts University School of Medicine; 2Warren Alpert Medical School of Brown University; 3Tufts Medical Center, Department of Neurosurgery; 4Tufts Medical Center, Department of Otolaryngology-Head and Neck Surgery
Introduction: Intracranial meningiomas are one of the most common CNS tumors. While often benign, there is significant potential morbidity for large or malignant tumors. The Affordable Care Act (ACA) has been shown to increase access to care and lead to earlier diagnoses, particularly for underserved populations. Research has shown that non-White or lower socioeconomic status (SES) patients tend to have later diagnoses and present with more serious disease.
Objectives: The impact of Medicaid expansion on the incidence of intracranial meningioma has not yet been determined. The goal of this study was to determine if Medicaid expansion was associated with a change in incidence of intracranial meningiomas in expansion states versus non-expansion states. Total incidence was investigated, as well as associations with race, county SES, and tumor behavior.
Methods: A difference-in-difference (DID) analysis was conducted on intracranial meningioma data from the Surveillance, Epidemiology, and End Results (SEER) database between January 1, 2010 and December 31, 2019. This analysis compared the change in intracranial meningioma incidence rate between counties that adopted Medicaid expansion in 2014 (intervention group) to those that did not (control group). States that expanded during the study period were excluded. Additional SEER data was obtained to separate cases into race, county SES, and ICD-O-3 behavior (benign, borderline malignant, and malignant) breakdowns.
Results: The study included 162,200 cases from 1,021 counties. Medicaid expansion did not impact overall intracranial meningioma incidence (p=0.150). However, it did allow for increased identification of more aggressive tumors: benign cases saw a 2% relative decrease (p=0.002), borderline cases saw a 22% relative increase (p<0.001), and malignant cases saw a 25% relative increase (p<0.001). Additionally, Black populations saw a 4% relative increase (p<0.001) and Hispanic populations saw a 2% relative increase (p<0.001), whereas White populations saw a 7% relative decrease (p<0.001) and Asian/Pacific Islander (API) populations were not significantly impacted (p=0.308). Triple DID analysis of county SES found an 8% relative decrease (p<0.001) for high SES counties, and no significant impact in low SES counties (p=0.272).
Conclusion: Medicaid expansion was not associated with a change in overall intracranial meningioma incidence. However, Medicaid expansion was associated with a relative increase in incidence of borderline malignant and malignant meningiomas, as well as for Black and Hispanic populations. These findings demonstrate the impact of Medicaid expansion on increased access to care for the most cost-intensive forms of intracranial meningioma.
