Sept. 17, 2025 — A new study from the Harvey L. Neiman Health Policy Institute found that office-based imaging studies were more likely to be repeated within 90 days when the initial study was interpreted by a non-physician practitioner (nurse practitioner or physician assistant, NPP) than when interpreted by a radiologist. The study, published in the Journal of the American College of Radiology (JACR), was based on 1.3 million Medicare imaging claims between 2013 and 2022.
Researchers compared repeat imaging rates for studies initially interpreted by NPPs to those initially interpreted by radiologists and examined whether the patient had repeat imaging in the same imaging family (i.e., same anatomic region and imaging modality) within 90 days. Overall, 12.5% of studies had repeat imaging with the rate varying be modality: 15.9% for radiography, 4.6% for ultrasound, and 3.8% for MR.
“Repeat imaging rates were substantially higher for imaging studies interpreted by NPPs for each modality studied: 20.4% vs 14.6% for radiography, 11.6% vs 4.5% for ultrasound, and 8.8% vs 3.8% for MR,” said Eric Christensen, PhD, Research Director at the Neiman Institute and lead author of the study. “After adjusting for patient characteristics, the odds of repeat imaging for NPP versus radiologist interpreted studies were 35%, 141%, and 156% higher for radiography, ultrasound, and MR, respectively.”
The authors note that while the study cannot determine the ideal repeat imaging rate, the differences suggest that interpretation by radiologists may help reduce avoidable imaging. This has implications for delayed diagnosis and treatment, healthcare costs, and radiation exposure.
“Repeat imaging is a potential source of unnecessary imaging when it can be avoided with high quality initial imaging,” said Elizabeth Rula, PhD, Executive Director of the Neiman Institute. “The lower repeat imaging rates we observed for studies interpreted by a radiologist underscores the importance of specialized training in diagnostic imaging. Avoiding unnecessary repeat imaging through quality interpretation and reporting helps patients get the correct diagnosis first, allowing for expedient treatment and cost avoidance.”
“Various studies have found that the percentage of studies interpreted by NPPs has continued to increase as the number of NPPs has increased over time,” said Dr. Christensen. “With NPPs expected to increase by one-third by 2033, there is likely to be commensurate growth in NPP-interpreted imaging, and with this growth, understanding how it affects care delivery, with implications for quality and value, is an important clinical and policy question.”
For more information on the Harvey L. Neiman Health Policy InstituteVisit www.neimanhpi.org.
November 02, 2026 
