The US Preventive Services Task Force (USPSTF) has published a draft recommendation for the use of the Ankle Brachial Index (ABI) for screening of peripheral artery disease (PAD). The USPSTF is seeking comments from the vascular healthcare community on these recommendations, which are as follows:
“In deciding whether to screen for PAD with ABI in asymptomatic adults, clinicians should consider the following.
Potential preventable burden. The true prevalence of PAD in the general population is not known. Recent data on the prevalence of low ABI (≤0.9) from the NHANES show that 5.9% of the U.S. population age 40 years and older (7.1 million people) have a low ABI (1). More than half of people with a low ABI do not exhibit typical symptoms of PAD. No information is available on what proportion of these patients will go on to develop symptoms; however, PAD is an indicator of CVD. Studies estimate that over 5 years among persons with stable claudication but not critical ischemia, approximately 70% to 80% will remain stable, while 10% to 20% will experience worsening claudication and 1% to 2% will develop critical ischemia (6). Similar data are not available for asymptomatic patients with a low ABI.
Potential harms. While there are minimal harms associated with the ABI procedure itself, there are possible downstream harms. False-positive results, anxiety, labeling, and exposure to gadolinium or contrast dye if either MRA or CTA is used for confirmation of the diagnosis may occur. Use of ABI in conjunction with FRS has the potential to reclassify individuals. Given the uncertainty of the appropriateness of such reclassifications, this could result in patients either being reclassified to a higher risk category and receiving additional treatments, with the resultant adverse effects, or being reclassified to a lower risk category and discontinuing treatments that might be beneficial (5).
Cost. The cost of performing ABI is mainly in time and staff resources, as it takes approximately 15 minutes to perform the test in the office setting (6). Additionally, new equipment that performs pulse volume recordings or Doppler wave form tracings may need to be purchased (6).
Provision of this test to asymptomatic individuals may divert time away from other prevention activities that might be more beneficial to that particular patient.
Current practice. A survey of primary care practices across the United States found that nearly 70% of providers report never using ABI in their practice settings, 6% to 8% report using ABI once a year, and only 12% to 13% report using ABI weekly or monthly (7).”
Visit the USPSTF recommendations for more information and to submit your comments. The USPSTF is seeking comments until April 15, 2013. Also see these resources for more PAD screening information:
- “Agreement of Community-Performed Ankle Brachial Pressure Indices (ABPI) with Vascular Laboratory Performed Assessment“
- “Critical Limb Ischemia: An Overview of the Epidemiologic and Clinical Implications“
- “Color Doppler Evaluation of the Pedal Arteries as a Predictive Tool in Peripheral Arterial Disease“