A new Harvey L. Neiman Health Policy Institute study, published in the American Journal of Roentgenology (AJR), investigated whether office-based providers are more likely to refer imaging to a radiologist, or to self-refer and interpret the ordered imaging studies themselves. “Self-Interpretation of Imaging Studies by Ordering Providers: Frequency and Associated Provider and Practice Characteristics” found that 43.6% of office-based studies were interpreted by the ordering provider, while 58.5% were interpreted within the ordering provider’s practice. Additionally, rates of self-interpretation varied by the specialty of the ordering provider and the imaging modality.
Self-Read Rates Vary by Modality and Specialty
Based on more than 1.6 million office-based imaging claims for Medicare fee-for-service beneficiaries in 2022 that were ordered by non-radiologists, by modality and across all specialties, this AJR Original Research manuscript by Christensen et al. found that the self-interpretation rate for office-based imaging was as follows:
- 50.4% for radiography and fluoroscopy
- 52.0% for ultrasound
- 39.5% for nuclear medicine
- 5.3% for CT
- 6.1% for MR
Meanwhile, self-interpretation by specialty broke down accordingly:
- 19.9% for primary care physicians
- 75.7% for orthopedic/sports medicine physicians
- 30.5% for non-physician practitioners
Another key determinant of self-interpretation rates was the size of the practice. Rates of self-interpretation were substantially less in the largest practices (500 or more providers) than the smallest practices (only 1-9 providers): 24.2% versus 48.9%, respectively, according to the researchers’ findings.
Access to Radiologists Could Curb Self-Reading
Whether or not there was a radiologist in the ordering provider’s practice was highly correlated with self-interpretation of imaging by the ordering provider (Fig. 1). “If there was a radiologist in the practice, the odds of self-interpretation were about one-half compared to practices without a radiologist on staff,” said Eric W. Christensen, PhD, research director at the Neiman Institute in Reston, VA. “Conversely, the odds of within-practice interpretation were generally 2 to 3 times higher if there was a radiologist in the practice.”
Continuing consolidation of health care—“which is creating larger, multispecialty practices,” Dr. Christensen added—could reduce imaging self-interpretation via increased access to radiologists within practice. “Such centralization of radiology services may encourage referral of imaging interpretation to the within practice radiologist, in lieu of potential self-interpretation.”
Training Gaps, Policy Questions, and Equity Decisions Remain
“Our results raise potential implications for quality of patient care. Nonradiologist specialties, aside from cardiology, lack the rigorous and comprehensive training in imaging interpretation that occurs during the 4 years of a radiology residency program,” said Vijay M. Rao, MD, senior vice president of enterprise radiology at Jefferson Health and professor of radiology at Thomas Jefferson University in Philadelphia, PA.
Pointing out that some specialties may provide targeted training in imaging interpretation that is narrow in scope, such as in ultrasound for emergency medicine or obstetrics/gynecology, “the large differences between radiologists and non-radiologists in interpretation training could lead to differences in diagnostic accuracy,” Dr. Rao said.
And as Kerry L. Thomas, MD, noted in her AJR Editorial Comment, while defined personnel qualifications—including for the interpreting physician—are clearly delineated when accrediting outpatient imaging centers, “such quality standards are lacking for the interpreting provider of in-office examinations.”
Importantly, to avoid secondary disparities related to health care quality, “images should be interpreted by providers with appropriate training for the specific examination being reviewed, agnostic of the care setting,” said Dr. Thomas from H. Lee Moffit Cancer Center and the department of diagnostic imaging and interventional radiology at University of South Florida’s Morsani College of Medicine in Tampa.
A “Stark” Surprise
Concerns of financial conflicts of interest related to self-referral contributed to the passage of the federal Stark Law in 1989. Named after U.S. House Representative Pete Stark of California, the Stark Law prohibits physician self-referral for designated health services, including radiology, under Medicare. Over time, certain exceptions (à la the in-office ancillary services rule) were added to allow necessary in-practice imaging referrals within guidelines.
Intended to curb the practice of self-referral, in reality, there remain too few restrictions on imaging interpretation by non-radiologists. And as the authors of this AJR article found, the Stark Law’s in-office ancillary exception greatly weakens its ability to restrict imaging self-referral. “Hence, our results highlight a need to revisit the in-office ancillary exception policy to impact the potential financial incentives that lead to self-referral,” Dr. Rao concluded.