Trends in Diagnostic Imaging by Nonphysician Practitioners and Associations With Urbanicity and Scope-of-Practice Authority

Abstract

Objective: We aimed to assess the changing share of diagnostic imaging billed by NPPs and how such changes differ by urbanicity within the context of scope-of-practice (SOP) regulations and legislation.

Methods: This retrospective cohort study used patient claims for diagnostic imaging studies spanning 2016-2020 from Optum Clinformatics Datamart datasets. Multivariable modeling determined the odds of patients receiving NPP-interpreted vs physician-interpreted imaging. Imaging rates and trends in proportions of NPP-billed claims were assessed by urbanicity and relative to other factors including SOP, imaging modality, and place of service.

Results: Of all identified imaging claims, 3,348,881 (3.0%) were attributed to NPPs, with the highest rates of NPP interpretations per 10,000 images occurring in rural and small-town areas. From 2016 to 2020, the rate of NPP-billed imaging increased from 257 to 331 claims per 10,000 beneficiaries (P = 0.004), observed across both metropolitan (240 to 315, P = 0.001) and micropolitan (367 to 436, P = 0.020) settings. Although rates in rural and small-town areas rose, the increase was not significant (330 to 392, P = 0.363). Rises in NPP imaging in metropolitan settings occurred in states with moderately restrictive (307 to 358, P = 0.008) and least restrictive (289 to 419, P = 0.004) SOP legislation.

Discussion: Rates of diagnostic imaging interpretation by NPPs are rising. Growth in recent years appears driven by metropolitan areas in states with less restrictive SOP regulations. Future work is necessary to assess the quality of and downstream costs related to increasing NPP-interpreted imaging.