Non-Physician Practitioner Imaging Interpretations Doubled Over Last Decade
Non-physician practitioners’ (NPPs) share of imaging interpretation in office-based practices increased 117%, from 2.52% of Medicare imaging studies in 2013 to 5.47% in 2022, according to a new Harvey L. Neiman Health Policy Institute study. Interpretations by NPPs are performed by a small minority (5.55%) of NPPs with considerable variation by imaging modality and state. Published in the Journal of the American College of Radiology, the study was based on over 20 million office-based imaging studies for Medicare fee-for-service beneficiaries (2013-2022).
The study researchers’ examination of office-based NPP interpretation patterns included the characteristics of the NPP providers and differences by state, the primary physician specialty of their employment practice, and by imaging modality. Their results revealed similar growth in NPP interpretation share of office-based imaging across all diagnostic imaging modalities.
“We found that the NPP interpretation share more than doubled for x-ray (+114.5%), ultrasound (+124%), CT (+123.6%), and MR (+134.8%) and nearly doubled for nuclear medicine (+86.7%),” said Eric Christensen, PhD, Research Director at the Neiman Health Policy Institute. “This growth was fueled by a 141% increase in the number of NPPs providing care to Medicare patients over the decade (2013-2022).”
When the characteristics of NPPs who interpreted imaging were examined compared to those who did not, a number of differences were evident. “Male NPPs were 61% more likely than female NPPs to interpret imaging, those younger than 55 were 41-43% more likely to interpret imaging than those 65 or older, and those in smaller practices were 2 to 3 times more likely to interpret imaging than those in large practices,” said Dr Richard Duszak, Professor and Chair, Department of Radiology, University of Mississippi Medical Center. “With new NPPs entering the workforce at an increasing pace, this age discrepancy suggests that the growth of NPP imaging interpretation could further accelerate, drawing additional attention to considerable mismatches in education and training for imaging interpretation when compared with radiologists.”
The study showed that NPP interpretation rates varied widely across states and with different patterns by modality. For example, NPPs interpreted more than 16% of x-rays in Alaska, Idaho, and Montana but <1% in Hawaii. For CT, NPPs interpreted 2% in Utah and South Dakota with many states having no interpretation by NPPs. Dr Christensen explained, “While our study does not permit us to assert definitive reasons for dramatic state-level variation, we believe this could be related to regional radiologist and other physician manpower shortages as well as differences in state laws and regulations such as with NPP scope of practice.”
NPP interpretation share was also found to differ by the NPP’s employer practice specialty. The study showed that NPPs employed by primary care and orthopedic practices accounted for a combined 74% of all imaging interpreted by NPPs. Specifically, Dr Duszak noted certain interesting results. “We found an unexpectedly high share of NPP interpretation of sinus CT in otolaryngology practices, and spine and extremity joint MRI interpretation by NPPs in orthopedic practices. Given that such studies are frequently interpreted by subspecialist radiologists, this raises questions about the differential adequacy of NPP training in radiology and the associated quality of their interpretations.”