title: The relevance of different methods of calculating the ankle-brachial index: the multi-ethnic study of atherosclerosis.
abstract: The authors aimed to determine differences in the prevalence of peripheral arterial disease (PAD) and its associations with cardiovascular disease (CVD) risk factors, using different methods of calculating the ankle-brachial index (ABI). Using measurements taken in the bilateral brachial, dorsalis pedis, and posterior tibial arteries, the authors calculated ABI in 3 ways: 1) with the lowest ankle pressure (dorsalis pedis artery or posterior tibial artery) ("ABI-LO"), 2) with the highest ankle pressure ("ABI-HI"), and 3) with the mean of the ankle pressures ("ABI-MN"). For all 3 methods, the index ABI was the lower of the ABIs calculated from the left and right legs. PAD was defined as an ABI less than 0.90. Among 6,590 subjects from a multiethnic cohort (baseline examination: 2000-2002), in comparison with ABI-HI, the relative prevalence of PAD was 3.95 times higher in women and 2.74 times higher in men when ABI-LO was used. The relative magnitudes of the associations were largest between PAD and both subclinical atherosclerosis and CVD risk factors when ABI-HI was used, except when risk estimates for PAD were less than 1.0, where the largest relative magnitudes of association were found using ABI-LO. PAD prevalence and its associations with CVD risk factors and subclinical atherosclerosis measures depend on the ankle pressure used to compute the ABI.
authors.affiliation: Department of Family and Preventive Medicine, School of Medicine, University of California, San Diego, 9500 Gilman Drive, Mailcode 0811, La Jolla, CA 92093-0811, USA. mallison@ucsd.edu
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Allison
authors.forename: Victor
authors.initials: V
authors.lastname: Aboyans
authors.forename: Tanya
authors.initials: T
authors.lastname: Granston
authors.forename: Mary M
authors.initials: MM
authors.lastname: McDermott
authors.forename: Aruna
authors.initials: A
authors.lastname: Kamineni
authors.forename: Hanyu
authors.initials: H
authors.lastname: Ni
authors.forename: Michael H
authors.initials: MH
authors.lastname: Criqui
mesh_terms: D001741:Black or African American; D000368:Aged; D000369:Aged, 80 and over; D055109:Ankle Brachial Index / Q000379:methods*; D001213:Asian; D050197:Atherosclerosis / Q000150:complications* / Q000175:diagnosis / Q000208:ethnology; D015331:Cohort Studies; D003710:Demography; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D016491:Peripheral Vascular Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000208:ethnology; D015995:Prevalence; D012307:Risk Factors; D044465:White People