PATHOPHYSIOLOGY AND NATURAL HISTORY PERIPHERAL VASCULAR DISEASE The prevalence of peripheral arterial disease in a defined population

Because patients with peripheral arterial disease (PAD) may be asymptomatic or may present with atypical symptoms or findings, the true population prevalence of PAD is essentially unknown. We used four highly reliable, sophisticated noninvasive tests (segmental blood pressure, flow velocity by Doppler ultrasound, postocclusive reactive hyperemia, and pulse reappearance halftime) to assess the prevalence of large-vessel PAD and small-vessel PAD in an older (average age 66 years) defined population of 613 men and women. A total of 11.7% of the population had large-vessel PAD on noninvasive testing, and nearly half of those with large-vessel PAD also had small-vessel PAD (5.2%). An additional 16.0% of the population had isolated small-vessel PAD. Large-vessel PAD increased dramatically with age and was slightly more common in men and in subjects with hyperlipidemia. Isolated small-vessel PAD, by contrast, was essentially unrelated to sex, hyperlipidemia, or age, although it was somewhat less common before age 60. Intermittent claudication rates in this population were 2.2% in men and 1.7% in women, and abnormalities in femoral or posterior tibial pulse were present in 20.3% of men and 22.1% of women compared with the noninvasively assessed large-vessel PAD rate of 11.7%. Thus assessment of large-vessel PAD prevalence by intermittent claudication dramatically underestimated the true large-vessel PAD prevalence and assessment by peripheral pulse examination dramatically overestimated the true prevalence. Circulation 71, No. 3, 510-515, 1985. THE PREVALENCE of peripheral arterial disease (PAD) in the general population is essentially unknown, primarily because of the lack of data on asymptomatic PAD. Most studies have focused on symptomatic or clinical populations, and previous reports in free-living populations are limited to assessment by symptoms, pulse palpation, or older noninvasive tests. 1-13 Recently, highly reliable and valid noninvasive tests for PAD have been developed. These newer methods permit accurate, risk-free evaluation of PAD in subjects unselected for symptoms.' l9 We used such noninvasive tests in a defined, freeliving population to determine the true prevalence of PAD and the degree of error resulting from assessment From the School of Medicine, University of California, San Diego, La Jolla. Supported by National Institutes of Health grant HL 22255. Dr. Criqui is the recipient of a Research Career Development Award (HL 00946) from the National Heart, Lung, and Blood Institute. Address for correspondence: Michael H. Criqui, M.D., M.P.H., Division of Epidemiology, Department of Community and Family Medicine, M-007, University of California, San Diego, La Jolla, CA 92093. Received Aug. 31, 1984; revision accepted Dec. 13, 1984. 510 ofPAD by the traditional methods, intermittent claudication and pulse palpation.