While the number of nuclear myocardial perfusion imaging (MPI) exams performed among members of the Northern California Kaiser Permanente health plan increased substantially during the first six years of the 2000s, those numbers fell just as precipitously over the next five years, according to newly published research in the Journal of the American Medical Association.
The study, published March 26, found that the number of nuclear MPI tests performed increased by 41 percent from 2000 to 2006, then dropped by 51 percent from 2006 to 2011.
According to the study, led by Edward J. McNulty of Kaiser Permanente Medical Center in San Francisco, the declines from 2006 to 2011 were greater for outpatients (58 percent) than inpatients (31 percent), and for persons under the age of 65.
The authors determined that the use of cardiac computed tomography increased during this time and could have accounted for up to 5 percent of the decrease, but that the total decrease was not due to an increase in the use of imaging modalities other than nuclear MPI.
"Although the abrupt nature of the decline suggests changing physician behavior played a major role, incident coronary disease, as assessed by [heart attack], also declined [by 27 percent]," the authors wrote. "We could not determine the relative effects of these factors on MPI use."
They concluded that the reduction in MPI testing "demonstrates the ability to reduce testing on a large scale with anticipated reductions in healthcare costs."
The Medical Imaging & Technology Alliance (MITA) released a statement in response to the study, citing it as further evidence that medical imaging utilization is continuing to fall.
"A number of recent studies--including analyses from the Medicare Payment Advisory Commission--have confirmed that utilization of medical imaging technologies is on the decline," MITA Executive Director Gail Rodriguez said. "The drop in MPI tests again delegitimizes misguided policy efforts to curb access to medical imaging services by allowing radiology benefits managers to intrude on patient-physician decision making."