Emergency Department Radiology: Study Shows Higher Imaging Orders by NPPs

A new study of nearly 17 million emergency department (ED) visits by Medicare beneficiaries between 2005 and 2020 revealed the presence of non-physician practitioners (NPPs) was associated with a 5.3 percent increase in imaging.

Researchers have seen two emerging trends in emergency departments (EDs) in the United States. In 2018, 35.3 million ED visits involved a non-physician practitioner (NPP), a nearly 6.8-fold increase from 5.2 million ED visits reported in 1997.1,2 Between 2004 and 2014, researchers noted a 29 percent increase in imaging studies per ED visit with computed tomography (CT) accounting for the majority of the increase.3

Is there a correlation between these trends? Researchers examined this question in a recently published study in JAMA Network Open. After reviewing a Medicare database of 16,922,274 ED visits that took place between 2005 and 2020, the study authors found that EDs with NPPs had a 5.3 percent increase in imaging per ED visit in comparison to EDs with no NPPs.4

The study authors also noted the presence of NPPs in EDs were associated with a 7.3 percent increase in CT orders, a 3.2 percent increase in radiography and a combined 14.2 percent increase in ordering other imaging modalities.4

While acknowledging that NPPs in EDs can increase patient access to care and at a lower Medicare reimbursement rate than physicians, the study authors suggested that facilities also consider the costs of increased imaging use among NPPs.

“Because the Medicare Physician Fee Schedule pays for services rendered by NPPs at 85% of what it pays physicians, NPPs deliver care at a lower cost if their use of concurrent and downstream services is the same as that of physicians. However, such a cost advantage is offset to the degree that NPPs are associated with higher resource use. Thus, our findings are important because they show a higher use of imaging studies across all modalities,” wrote lead study author Eric W. Christensen, Ph.D., the director of Economics and Health Services Research and adjunct professor of Health Services Management at the the University of Minnesota, and colleagues.

(Editor’s note: For related articles, see “Medicare Claims Study Shows Increasing Utility of PAs and NPs in Radiology Practices” and “Is CT Overutilized in the ER for Suspected Urinary Stone Disease?”)

The study authors also found that EDs with NPPs had a 3.4 percent increase in visits that had imaging as well as a 2.2 percent increase in the amount of imaging for patients who had imaging in comparison to EDs without NPPs. The NPPs in EDs were also associated with increased imaging across different diagnosis groups, including an 11.7 percent higher use of imaging for neoplasms in comparison to EDs with no NPPs.4

In order to address these variations and help ensure appropriate imaging, Christensen and colleagues suggested clinician-specific training on the timing and kind of imaging necessary for clinical conditions.

“To the degree that NPPs in the ED use more imaging than physicians, their increased role in ED care may represent an opportunity for initiatives to ensure their judicious use of imaging,” noted Christensen and colleagues.

In regard to study limitations, the researchers noted that joint management by physicians and NPPs on some ED visits billed by physicians may have contributed to an underestimation of the impact of NPPs on image ordering. They also acknowledge that state differences in scope of practice for NPPs may influence image ordering patterns.

References

1. Menchine MD, Wiechmann W, Rudkin S. Trends in midlevel provider utilization in emergency departments trends from 1997 to 2006. Acad Emerg Med. 2009;16(10):963-969.

2. Cairns C, Kang K, Santo L. National hospital ambulatory medical care survey: 2018 emergency department summary tables. Centers for Disease Control and Prevention. Available at: https://www.cdc.gov/nchs/data/nhamcs/web_tables/2018-ed-web-tables-508.pdf . Accessed November 10, 2022.

3. Selvarajan SK, Levin DC, Parker L. The increasing use of emergency department imaging in the United States: is it appropriate? AJR Am J Roentgenol. 2019;213(4):W180-W184.

4. Christensen EW, Liu CM, Duszak Jr R, Hirsch JA, Swan TL, Rula EY. Association of state share of nonphysician practitioners with diagnostic imaging ordering among emergency department visits for Medicare beneficiaries. JAMA Netw Open. 2022;5(11):e2241297. doi: 10.1001/jamanetworkopen.2022.41297.