1923. Increased Head CT Angiography and CT Perfusion Utilization Among Medicare Beneficiaries from 2010-2018
Authors * Denotes Presenting Author
  1. Jeffrey Elsner *; The Johns Hopkins School of Medicine
  2. Andrew Kolarich; The Johns Hopkins Hospital
  3. Haris Sair; The Johns Hopkins Hospital
  4. Sachin Gujar; The Johns Hopkins Hospital
In the 2010s, a series of prominent multicenter, randomized controlled trials were conducted that assessed the benefit of endovascular thrombectomy versus standard management in selected patients with ischemic stroke (1-6). Their results consistently demonstrated superior functional outcomes in the thrombectomy groups. Computed Tomography Angiography of the head (CTA) and cerebral CT Perfusion (CTP), as well as magnetic resonance protocols, were used to identify appropriate patients for treatment in these trials. Here, we analyze a large national database to evaluate whether CTA and CTP saw corresponding increases in utilization over the years 2010-2018, with special interest around 2016 and 2018, the years after the aforementioned trials were published.

Materials and Methods:
This analysis was performed on the Physician Summary Supplier Master Files, a publicly accessible database published by the Centers for Medicare Services. The institutional review board granted exemption for this study. CT Angiography of the head was identified using Common Procedural Terminology (CPT) code 70496, while CT Perfusion was identified using code 0042T. Variables evaluated included total number of Medicare beneficiaries and numbers of CTA and CTP studies per annum. Statistical analysis was performed with SPSS version 25 (2017 IBM Corporation, Armonk NY).

From 2010 to 2018, the total number of Medicare fee-for-service beneficiaries increased from 36.0 million to 38.7 million persons. Total number of CTA studies increased each year from 138,189 to 474,393 per annum, a gain of 243%. Total number of CT Perfusion studies increased each year from 10,096 to 41,620 per annum, a gain of 312%. After adjustment for Medicare enrollment, these values represent an increase in CTA utilization from 383.9 to 1,226.9 per 100,000 persons per year, and an increase in CTP utilization from 28.0 to 107.6 per 100,000 persons per year. Of note, the two year-over-year increases in 2015-2016 and 2017-2018 accounted for most of the overall increase in both CTA utilization (67% of gains) and CTP utilization (87% of gains). These two 1-year intervals each correspond to the year following publication of the trials discussed above.

Our analysis of a database capturing more than 36 million Medicare beneficiaries reveals that on a per capita basis, use of both head CT Angiography and cerebral CT Perfusion studies increased several-fold from 2010-2018. In an encouraging trend, the majority of these increases occurred in the immediate wake of prominent randomized trials that utilized CTA and CTP in selecting ischemic stroke patients likely to benefit from endovascular thrombectomy.