Potential Effect of the Protecting Access to Medicare Act on Use of Advanced Diagnostic Imaging in the Emergency Department: An Analysis of the National Hospital Ambulatory Care Survey.

Background Clinical decision support is increasingly used to enhance clinicians' exposure to established evidence and patient information during an episode of patient care. Pending legislation specifies clinical decision support before performing advanced imaging at emergency department (ED) visits. Purpose To estimate the volume of advanced imaging tests (CT and MRI) that would require use of clinical decision support to achieve Protecting Access to Medicare Act (PAMA) compliance in the ED. Materials and Methods A retrospective, cross-sectional analysis of ED visits was conducted by using data from the 2012-2015 National Hospital Ambulatory Care Survey. PAMA-related visits were identified by selecting the patient reasons for visit (RFVs) related to the eight clinical conditions. Results Among the adult ED visits, 26.7% (20 506 of 77 299, representing 113 000 000 visits across 4 years, or 28 000 000 visits annually) patients presented with a RFV consistent with a PAMA priority clinical area (PCA). Among visits in which a patient described an RFV code consistent with a PAMA PCA, up to 22.9% (4681 of 20 506; 95% confidence interval: 21.8%, 24.1%) patients underwent advanced imaging, translating to approximately 6 000 000 visits annually. Conclusion Protecting Access to Medicare Act legislation targets eight priority clinical areas, estimated to be prevalent among one in four adult emergency department visits. CT and/or MRI studies are performed during up to 23% of these visits. Depending on the particular clinical decision support systems selected within a health system, and how they are implemented, the potential volume of studies in which clinicians must interact with clinical decision support system may either exceed or fall short of these estimates. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Forman in this issue.