Secondary interpretations of diagnostic imaging examinations have increased significantly among Medicare beneficiaries, according to a new study published by the Journal of the American College of Radiology. The authors also noted that denial rates for these secondary interpretations are “uniformly low.”
“Concordant with the prior work focusing exclusively on CT, we found broad increases in secondary imaging service interpretations across a variety of imaging services, with some families showing particularly rapid growth,” wrote lead author Andrew B. Rosenkrantz MD, MPA, of the department of radiology at NYU Langone Medical Center in New York, and colleagues. “Of note, these increases occurred despite the absence of comparable growth in primary imaging interpretations.”
Rosenkrantz et al. studied Medicare data to track secondary interpretations of a variety of imaging services from 2003 to 2016. The authors identified such interpretations by looking for modifiers 26 and 77.
Overall, between 2003 and 2016, there were more than 9.7 million radiography and fluoroscopy (R&F) secondary interpretations billed to Medicare. There were also more than 568,000 CT secondary interpretations, more than 105,000 for ultrasound, more than 84,000 for MRI and more than 23,000 for nuclear medicine.
Looking at changes in the utilization of secondary imaging interpretations from 2003 to 2016, the authors found that cardiac MRI (+35.7 percent), breast MRI (+33.1 percent), abdominal and pelvic MRI (+30.3 percent), unspecified nuclear medicine (+27.9 percent) and head and neck CT (+25.3 percent) had the highest compound annual growth rates.
In addition, service family included in the study had a secondary interpretation denial rate of less than 25 percent. It was less than 10 percent for 15 service families, including chest CT (5.2 percent), abdomen/pelvis MR (6.1 percent), chest R&F (6.2 percent), abdomen/pelvis R&F (6.4 percent) and extremity MR (6.5 percent).
Rosenkrantz and colleagues anticipated secondary interpretations would be on the rise for CT and MRI, but the data did reveal some unexpected findings.
“Surprisingly, we found that secondary interpretations, as indicated by a combination of modifiers Medicare has instructed radiologists to use in reporting these services, overwhelmingly involved chest radiography,” the authors wrote. “In this context, questions arise as to the specialty and subspecialization of health care providers initially interpreting and billing for these services. The extremely high frequency of billed secondary interpretations for chest radiology, we believe, should prompt a closer examination of the specialty and practice site of providers delivering initial services.”
The authors concluded that these increases in secondary interpretations should be taken seriously by both policymakers and imaging leaders.
“Secondary interpretations have the potential to render more accurate interpretations, alter patient management, and lower rates of repeat imaging examinations, which in turn may entail additional exposure to ionizing radiation and intravenous contrast agents as well as additional costs to patients and health care systems,” they wrote. “Policy considerations regarding appropriate payment for secondary interpretations should consider these downstream benefits.”