Supplementary Material for: Access to TACE and TARE with respect to region and urbanity in the United States: a large retrospective healthcare claims database study

Access to highly specialized interventional oncology procedures such as transarterial chemoembolization (TACE) and radioembolization (TARE) may be limited in non-metropolitan areas of the United States. This study characterizes the distribution of these procedures across regions by metropolitan status through utilization of a large commercial healthcare claims database (Truven Merative Marketscan). Patients with a diagnosis of primary hepatocellular carcinoma (HCC) (n= 41,280) were categorized into those who received TACE (n = 1,780) or TARE (n = 1,179). Chi-squared tests of association were utilized to analyze regional data. Statistical analyses showed significant differences between most regional comparisons with most patients receiving these procedures originating from metropolitan areas overall. Though limited to TACE and TARE, this study reveals a disparate distribution of TACE and TARE utilization across regions with preference towards metropolitan over non-metropolitan areas, which may represent a barrier for access to care for nonmetropolitan patients, though this remains to be studied.