The USPSTF just released its 8th Annual Report to Congress: High-Priority Evidence Gaps for Clinical Preventive Services, in which screening for peripheral arterial disease with the Ankle Brachial Index (ABI) is listed as one of the areas in need of better data before recommendations can be made.
The U.S. Preventive Services Task Force (USPSTF or Task Force) is an independent, volunteer group of national experts in prevention, primary care, and evidence-based medicine. The Task Force makes evidence-based recommendations about which clinical preventive services might improve quality of life or prolong life by identifying diseases at earlier stages when they are more treatable, or by reducing a person’s risk for developing a disease. Recommendations may include screening tests, behavioral counseling, and preventive medications.
Task Force recommendations must meet these 3 criteria:
- They apply only to people without signs or symptoms of the disease or health condition
- They focus on screening to identify disease early and other interventions to prevent the onset of disease
- They address services offered in the primary care setting or services to which patients can be referred by primary care professionals
Remember, per the criteria above, the USPSTF criteria only apply to people without signs of symptoms of the disease.
When the USWR was developing quality measures for patients with chronic wounds and ulcers, we wanted a quality measure that would involve screening for peripheral arterial disease. In 2009, I talked to representatives of the vascular medicine community and the individuals with whom I spoke were concerned that a measure like that would lead to too many invasive studies being performed, so they didn’t want to get behind it. I was surprised at that response. Patients with a non-healing lower extremity ulceration are not “without signs or symptoms,” as the USPSTF would put it. While it’s true they might not have peripheral arterial disease, they have SOME disease causing a persistent wound, and peripheral artery disease (PAD) is highly likely to be one of them.
Since the USWR “arterial assessment of patients with lower extremity ulcers” quality measure was approved by CMS in 2014, we’ve shown that the physicians who report peripheral arterial disease assessment have higher rates of healing for both venous leg ulcers and diabetic foot ulcers. That’s not because they are better at VLU compression or DFU off-loading than their peers – it’s because their PAD screening is better. They are finding un-diagnosed arterial disease. As for the method of assessment, we were very concerned that ABIs would not be sufficient for these patients. In fact, most practitioners are using transcutaneous oximetry or skin perfusion pressure, although some are using ABIs or toe pressure.
I don’t dispute the USPSTF or Task Force conclusion that PAD screening with an ABI has not been proven to be of value among asymptomatic patients. A patient with a chronic non-healing ulcer is NOT an asymptomatic patient – they are highly likely to have PAD. When they asked Willie Sutton, the bank robber, why he robbed banks, he replied, “Because that’s where the money is.” If you want to find a patient with PAD, start in the waiting room of the wound center. You won’t find normal, healthy people in the wound center waiting room – or at least, you shouldn’t. But you will find a lot of patients with PAD – that is, if you actually look.
- If you are looking for a Clinical Practice Improvement Practice for 2019, check out the USWR’s IA for improving arterial assessment of patients with lower extremity wounds and ulcers.
- Screening for Peripheral Artery Disease and Cardiovascular Disease Risk Assessment
With the Ankle-Brachial Index
- Peripheral Artery Disease and Cardiovascular Disease Risk: Screening With the Ankle Brachial Index
The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for peripheral artery disease and cardiovascular disease risk with the ankle-brachial index in asymptomatic adults. [italics mine]