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The mission of the Harvey L. Neiman Health Policy Institute® is to establish foundational evidence for health policy and radiology practice that promotes the effective and efficient use of health care resources and improves patient care.

July 7, 2023

Non-physician Practitioner Interpretation of Imaging Increased 27% between 2016 and 2020

A new study by the Harvey L Neiman Health Policy Institute found that rates of diagnostic imaging interpretation by non-physician providers (NPP) are on the rise from 2.6% to 3.3% of all imaging studies. The study, published in Current Problems in Diagnostic Radiology, found that the rate of NPP-billed imaging increased  27% from 2016-2020.

The study assessed over 110 million non-invasive imaging claims from the Optum® Clinformatics® Datamart from 2016 to 2020 – more than 3 million (3%) of which could be attributed to NPPs. Although the highest overall rates of NPP interpretation of images were seen in rural and small-town areas, the most significant growth in the rates of NPP-interpreted imaging over the study period were seen in both metropolitan (+31%) and micropolitan (+19%) areas.

“In previous studies evaluating the impact of expanding NPP scope of practice in a subset of U.S. states, we have shown that NPPs are associated with increased imaging utilization in the primary care and emergency department settings, meaning NPPs in these settings order more imaging than physicians,” explained Eric Christensen, PhD, Research Director at the Neiman Institute. “This study looked directly at NPPs practicing radiology and explored where, geographically, NPPs are contributing more to image interpretation.”

Another important facet of the study was the categorization of each provider by the scope-of-practice (SOP) regulations in his/her state. “As some states are granting NPPs greater autonomy, our finding that the greatest growth in NPP imaging was among those states with less stringent SOP laws matched our expectations,” notes Casey Pelzl, MPH, lead author of the study. She continued, “Interestingly, the growth in NPP-billed imaging was only observed in the metropolitan areas of states with less restrictive SOP legislation, but this growth was not echoed in micropolitan and small town/rural areas in these same states.”

The researchers also compared urban versus rural areas to determine if NPPs may play a role in expanding geographic access to radiology services. “While the historical higher rates of imaging by NPPs in more rural areas supported our access hypothesis, disproportionate growth in urban areas suggests other forces at play.  Although NPPs have been shown by some to increase access and decrease costs in the primary care setting, their value in providing highly specialized services such as image interpretation is unknown,” states Richard Duszak, MD, a coauthor, and the Chair of Radiology at the University of Mississippi Medical Center. “Our study did not assess the quality of imaging interpretation delivered by NPPs, but as this practice increases, need clearly exists for future study to inform future SOP laws around the country.”


To obtain a copy of the study or to arrange an interview with a Neiman Institute spokesperson, contact Nichole Gay at



About the Harvey L. Neiman Health Policy Institute

The Harvey L. Neiman Health Policy Institute is one of the nation’s leading medical imaging socioeconomic research organizations. The Neiman Institute studies the role and value of radiology and radiologists in evolving health care delivery and payment systems and the impact of medical imaging on the cost, quality, safety and efficiency of health care. Visit us at and follow us on TwitterLinkedIn and Facebook.


Nichole Gay
Harvey L. Neiman Health Policy Institute