Question marks over routine PAD screening in primary care
A new study questions the feasibility and value of primary care screening for peripheral arterial disease (PAD). The PIPETTE study is the first UK study of PAD prevalence for nearly a decade.
In total, 1101 individuals with ≥2 pre-identified CV risk factors but no known CV disease or diabetes were invited to participate. Participants underwent ankle-brachial index (ABI) measurement and QRISK2 assessment, and completed Edinburgh Claudication Questionnaires.
A total of 368 people participated in the study (participation rate: 33%).
The prevalence of PAD was 3% (n = 12). The number needed to screen (NNS) to detect one new case of PAD was 31. Refining the study population to those aged ≥50 years with a smoking history reduced the NNS to 14, while still identifying 100% of PAD cases. Of participants with PAD, 33% reported severe lifestyle-limiting symptoms of intermittent claudication that warranted subsequent endovascular intervention, yet had not previously presented to their GP. The QRISK2 score predicted high cardiovascular risk in 92% of participants with PAD.
Interestingly, adhering to the UK PAD guideline formulated by NICE — which recommends screening people with diabetes and those with symptoms of PAD or non-healing leg wounds — would have resulted in an NNS of 3, with only 42% of PAD cases being identified.
This study shows that targeting individuals aged ≥50 years that have a history of smoking could be an effective and efficient PAD screening strategy; however, results also suggest that QRISK2 could be a more amenable and comparable alternative for the identification of high CV risk in the primary care setting.
The low PAD yield and the fact that QRISK2 was largely comparable to the ABI in predicting high CV risk suggests that routine PAD screening may be unwarranted. However, larger studies in more ethnically diverse populations may be valuable to assess these results.
Davies J, et al. Primary care screening for peripheral arterial disease: a cross-sectional observational study. Brit J Gen Pract 2017;67(655):e103-e110 www.bjgp.org/content/67/655/e103
Taking the mystery out of peripheral arterial disease www.bjpcn.com/browse/editorial/item/1256-taking-the-mystery-out-of-peripheral-arterial-disease.html
Getting to grips with the ankle brachial index www.bjpcn.com/browse/editorial/item/1525-get-to-grips-withe-the-ankle-brachial-pressure-index.html