Prevalence and treatment patterns of lower extremity peripheral arterial disease among patients at risk in ambulatory health settings

Background

Lower extremity peripheral arterial disease (PAD) is underdiagnosed and undertreated in Canada, although data are limited. We sought to measure PAD prevalence and treatment patterns in ambulatory settings.

Methods

Five trained undergraduate pharmacy students screened subjects > 50 years of age in 10 community pharmacies and 4 physician offices in northern and central Alberta. We assessed cardiovascular risk factors, cardiovascular disease (CVD), and use of evidence-based therapies; administered the Edinburgh Claudication Questionnaire; and measured the ankle-brachial index (ABI). Patients with definite claudication but ABI > 0.90, or patients with ABI > 1.30 were referred to the study vascular medicine physician for further assessment. PAD was defined as an ABI ≤ 0.90 at the initial community screening or an exercise ABI of ≤ 0.90 and 20% lower than the resting ABI, or toe-brachial index of ≤ 0.70.

Results

We recruited 361 patients (65.1 ± 9.5 years old, 55% female, 85% white) between July 1 and November 30, 2008. Sixteen subjects had PAD (prevalence 4.4%; 95% confidence interval CI], 2.3-6.5), and all were previously unaware that they had PAD. Nine patients (2.5%) had PAD only, 7 (1.9%) had both PAD and CVD, 87 (24%) had CVD only, and 259 (72%) had neither PAD nor CVD. Use of antiplatelet agents (44%), angiotensin blockade (56%), or statins (44%) was low in patients with newly diagnosed PAD and without other CVD.

Conclusions

About 1 in 20 ambulatory persons > 50 years of age screened had PAD. All cases of PAD that we found were previously undiagnosed, and there was a large treatment gap for those without concomitant CVD.