Identifying Unrecognized Peripheral Arterial Disease Among Asymptomatic Patients in the Primary Care Setting

Abstract

National initiatives to enhance recognition of the detrimental impact of peripheral arterial disease on the health of adult Americans have been advocated. The objective of this study was to evaluate a strategy for identifying patients with unrecognized peripheral arterial disease from among persons without known atherosclerotic disease in the primary care setting. A cross-sectional design was used. Participants were patients receiving care from a multispecialty group practice in Massachusetts between July 2002 and July 2003, with a scheduled appointment with a primary care physician. Persons 70 years of age or older who were not already known to have atherosclerotic disease were enrolled. In addition, persons aged 50-69 with a diagnosis of diabetes mellitus, dyslipidemia, hypertension, and/or smoking based on information derived from administrative databases, and not known to have atherosclerotic disease, were enrolled. Before the scheduled appointment, potential study participants completed a telephone interview to ascertain their medical history. The ankle-brachial index (ABI) of eligible patients was measured at the time of the scheduled primary care office visit. Peripheral arterial disease was diagnosed if 1 or both legs had an ABI of ≤0.90. Also assessed was the time spent in performing ABI testing in a convenience sample of the study participants. ABI testing was performed on 717 patients. Among 359 study subjects aged ≥70 years, 45 (12.5%) were diagnosed with peripheral arterial disease. Nine (2.5%) of 358 subjects aged 50-69 years were diagnosed with peripheral arterial disease. The average total time (n=52) for ABI testing was 13.7 (SD: ±3.3) minutes. Patients aged ≥70 years required more time for ABI testing compared to those aged 50-69 (mean: 15.0 vs 13.0 minutes, p=0.04). Unrecognized asymptomatic peripheral arterial disease can be commonly detected among patients in the primary care setting who are not already known to have atherosclerotic disease. The yield from screening is substantially greater among unselected older patients compared with younger patients specifically identified as having risk factors for PAD. These findings should help inform the development and implementation of new initiatives to enhance the early detection of peripheral arterial disease among asymptomatic patients in the primary care setting.