Medical training and an exaggerated perception of benefit may drive overuse of myocardial perfusion imaging (MPI), a study found.
First author David E. Winchester, MD, FACP, and co-authors wanted to assess whether the single-payer Veterans Affairs (VA) health system would result in less inappropriate use of MPI. They conducted a retrospective cross-sectional investigation of 322 tests ordered in a single VA from December 2010 through April 2011.
Results appeared in a research letter published online June 10 in JAMA Internal Medicine.
Indications for the test were appropriate 78% of the time, inappropriate in 13% and uncertain in 8%. The most common inappropriate indications (16.7%) included testing of patients with low pretest probability who could have undergone treadmill electrocardiogram testing and asymptomatic patients with low coronary heart disease risk (16.7%). Of 9 preoperative MPI tests reviewed, 6 were inappropriate and 3 were appropriate.
Patient characteristics associated with inappropriate MPI tests included absence of symptoms (odds ratio [OR], 4.80; 95% confidence interval, 2.39 to 9.66; P less than .001). There was a lower likelihood of inappropriate testing with symptoms of chest pain (OR, 0.07; 95% CI, 0.02 to 0.20; P less than .001) and diabetes (OR, 0.37; 95% CI, 0.17 to 0.80; =.01).
Researchers noted that profit motives or defensive medicine didn't seem to apply, since the VA is a single-payer system and malpractice claims are mostly handled administratively.
Researchers wrote, "Conceivably, commonalities in medical training, independent of postgraduate practice environment, could contribute to an exaggerated perception of benefit of MPI in asymptomatic patients and those at low risk of coronary heart disease. This exaggerated perception of the benefit would also seem to hold true for preoperative risk assessment, with the majority of preoperative MPI in our study having been inappropriately ordered."