Overuse of Peripheral Arterial Disease (PAD) Testing Likely
Thursday, Dec. 03, 2015
Tests for peripheral arterial disease (PAD)—including the use of duplex ultrasound of lower extremities—are probably being overused, according to a study presented Wednesday.
The study, presented by David C. Levin, M.D., professor and chairman emeritus of the Department of Radiology at Jefferson Medical College and Thomas Jefferson University Hospital in Philadelphia, found that while the use of vascular ultrasound, as well as noninvasive physiologic testing (NPT), for PAD has flattened or even decreased since 2010, as of 2013 it was significantly higher than it was in 2001.
There has been some controversy surrounding the idea of screening for PAD. The U.S. Preventive Services Task Force has never recommended routine screening for PAD, while the Society of Interventional Radiology has long supported the idea of screening with its Legs for Life screening program.
According to Dr. Levin, one of the problems with this increased use of testing for PAD is that its prevalence in high-income countries is increasing at a relatively slow rate—about 1 percent annually. "So it's not increasing very rapidly," he said.
Dr. Levin also argued that there really is no need to treat asymptomatic patients with PAD. "It's a gradually progressive disease," he pointed out. "It doesn't have sudden catastrophic consequences like coronary or carotid disease where patients can be pretty much asymptomatic and all of a sudden present with a myocardial infarction or a stroke.
"So, it makes sense to try to screen patients [for those conditions like coronary or carotid disease] because you want to avoid those catastrophic conditions," he added. "But you really don't have to test anyone for PAD until they have a clinical story that tells you they have it."
That clinical story, he said, would be claudication—pain in the legs caused by too little blood flow while walking or during exercise.
"If a patient doesn't have leg pain when walking, he either doesn't have PAD or has a very mild case of it," Dr. Levin said. "The bottom line is that you really don't have to overuse those tests."
But when Dr. Levin and his colleagues analyzed Medicare Part B databases for 2001 through 2013 they found there had been sizeable increases in the use of these two tests. Exam volumes of lower extremity arterial ultrasound more than doubled (106 percent) during that time, while the number of NPTs increased by 79 percent.
And an analysis of use rates determined that lower extremity arterial ultrasound increased from 11.7 per 1000 in 2001 to 21.9 in 2013 (although it slightly decreased between 2010 and 2013).
Similar increases were seen with noninvasive physiologic tests (such as pulse volume recordings, segmental pressure measurements and ankle-brachial index tests). NPT volume increased from a rate of 21.0 per 1,000 in 2001 to a peak of 38.7 per 1,000 in 2010, before dropping back to 34.3 per 1,000 in 2013.
So the study provides both bad and good news, Dr. Levin said. "The bad news is that the utilization rates of both lower extremity ultrasound and non-invasive physiologic testing were quite a bit higher in 2013 than they had been in 2001. The good news is that since 2010 NPT utilization rates have actually gone down while ultrasound rates have basically stayed flat, so there is no more of that growth that we saw in earlier years."
The overall takeaway? "At a time when the prevalence of PAD was increasing only very slowly, the use of these tests increased much more rapidly, said Dr. Levin. "And that raises concerns about the overuse of these tests."