Billing claims for image interpretation handled by nonphysician providers such as nurse practitioners leapt by 27% during the five-period ending in 2020, according to a new analysis published Wednesday.

In particular, those living in small towns or rural areas had 30% higher chances that a nonphysician would interpret their exam compared to others in urban areas. The odds were even higher at 50% for others residing in “micropolitan” geographies (with populations between 10,000 to 50,000), experts detailed in Current Problems in Diagnostic Radiology.

One unexpected finding, according to the lead author: Urban areas saw significant increases in the number of interpretations handled by such nonphysician practitioners, or NPPs. This runs contrary to popular belief that small towns, facing struggles recruiting radiologists, are fueling this trend.

“We were surprised by the fact that the growth in NPP imaging was largely driven by metropolitan areas, especially since NPPs so often fill the care gaps seen in rural geographies,” Casey Pelzl, MPH, senior economics and health services analyst with the Harvey L. Neiman Health Policy Institute, told Radiology Business by email. “Although rural/small-town areas did show the highest rates/10,000 of NPP imaging, it was the significant upward trends in the metro areas that drove the overall increases we saw, suggesting that other factors aside from access are driving the observed growth.”

Pelzl and co-authors reached their findings by analyzing data from the Optum Clinformatics Datamart database of deidentified commercial claims. They included all claims for adults over 18 who received a radiography/fluoroscopy, ultrasound, CT, MRI or nuclear exam between 2016 and 2020. Researchers also excluded any claims in which the interpreting providers was not a physician, nurse practitioner or physician assistant.

The final sample included 110 million imaging claims from commercial insurers and Medicare Advantage plans. Of those, 3.3% or 3.3 million were handled by nonphysicians in 2020, up from 2.6% in 2016 (a 26.9% increase). The highest rate of NPP interpretations occurred in rural and small towns. During the study period, the rate of claims for NPP-interpreted exams increased from 257 per 10,000 beneficiaries up to 331 by 2020 (or nearly 29%). The uptick occurred across both metropolitan (rising from 240 per 10,000 to 315) and micropolitan (367 to 436 per 10,000) geographies. Increases in rural and small towns (330 to 392 per 10,000) were not statistically significant, the authors noted.

Pelzl et al. also found that NPP image interpretation increases in urban areas occurred both in states with moderately restrictive (307 to 358 per 10,000) and the least restrictive (289 to 419) rules around what duties nonphysicians can perform.  

“Scope-of-practice legislation does seem to have an effect on how NPPs actually practice in the context of radiology,” the study’s lead author told Radiology Business Thursday. “Patients imaged in states with moderately or minimally restrictive SOP laws were more likely to have their imaging performed and interpreted by an NPP versus a physician than those patients in states with stringent SOP legislation. Since several states are shifting toward granting NPPs more autonomy, this is something worth watching.”

The findings come after the American College of Radiology recently partnered with the AMA on a campaign to fight scope creep. Read previous coverage of the college’s efforts, and find a link to the study, below this story.