Imaging studies read by nonphysician practitioners (NPPs) are more likely to be repeated, according to a Harvey L. Neiman Health Policy Institute (HPI) report.
The findings highlight the benefit of specialized training when it comes to imaging exam interpretation, noted study coauthor Elizabeth Rula, PhD, executive director of the Neiman Institute. The results were published on September 17 in the Journal of the American College of Radiology.
"Repeat imaging is a potential source of unnecessary imaging when it can be avoided with high-quality initial imaging," Rula said in an HPI statement. "The lower repeat imaging rates we observed for studies interpreted by a radiologist underscore 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."
Differences in imaging patterns may suggest unnecessary care, noted the investigators, who were led by Eric Christensen, PhD, research director at HPI. The group sought to investigate any differences in repeat imaging rates between exams performed on Medicare fee-for-service beneficiaries and interpreted by NPPs versus a radiologist. Their research included 2013 to 2022 data from a CMS Research Identifiable File for 1.4 million imaging studies. Of this total number of exams, 12.5% were repeats.
Overall, the group reported that the odds of repeat imaging within 90 days for NPP versus radiologist interpreted studies were 35% for x-ray, 141% for ultrasound, and 156% for MRI. It also found the following:
Repeat imaging rates by type of exam interpreter | ||
Modality | NPPs | Radiologists |
| X-ray | 20.4% | 14.6% |
| Ultrasound | 11.6% | 4.5% |
| MRI | 8.8% | 3.8% |
Finally, the team noted higher odds ratios of repeat imaging depending on interpreter type:
- The odds ratio (OR) for repeat imaging was higher for NPP-interpreted versus radiologist-interpreted imaging: 1.35 for x-ray, 2.41 for ultrasound, and 2.56 for MRI.
- By anatomic region-modality, ORs ranged from 1.39 for shoulder x-ray to 3.4 for abdominal ultrasound.
Although the study findings can't necessarily determine the ideal repeat imaging rate, differences between NPPs and radiologists "suggest that interpretation by radiologists may help reduce avoidable imaging" -- a result that "has implications for delayed diagnosis and treatment, healthcare costs, and radiation exposure," the team noted.
"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," Christensen said. "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."
The complete study can be found here.
