Ankle-brachial index measured by palpation for the diagnosis of peripheral arterial disease.
BACKGROUND
The ankle-brachial index (ABI), i.e. the ratio of the ankle to brachial systolic blood pressure, is the golden standard for the diagnosis of peripheral arterial disease (PAD) and is a highly specific method for the assessment of vascular risk in otherwise asymptomatic patients.


OBJECTIVE
To assess the diagnostic accuracy of the ABI measured by palpation in patients at increased cardiovascular risk in a primary care setting.


METHODS
Twenty-four GPs enrolled 10 consecutive patients each, at intermediate cardiovascular risk, based on age >55 and <65 years and one or two associated major cardiovascular risk factors or age >65 and <80 years without associated cardiovascular risk factor. Clinical data recording and measurements of the ABI were performed. The design of the study was a prospective, blind comparison between the ABI measured by palpation by the GP and simultaneously by Doppler ultrasound by an angiologist (reference test).


RESULTS
Out of 240 enrolled patients, 205 completed the study (35 lost to follow-up); in 9, ABI by palpation was not measurable. Out of the remaining 196 assessable patients, 8 (4.08%) had PAD. Sensitivity of the palpation method was 88% (95% confidence intervals: 65-100), specificity 82% (77-88), positive predictive value 18% (6-29), negative predictive value 99% (98-100), positive likelihood ratio = 4.98 (3.32-7.48) and negative likelihood ratio = 0.15 (0.02-0.95).


CONCLUSIONS
The measurement of ABI by palpation in the setting of primary care, in patients at intermediate cardiovascular risk, is a sufficiently sensitive method to consider its use as a screening test for the exclusion of PAD.
Division of Internal Medicine, Ospedale della Valdichiana 'S.Margherita', USL 8, Arezzo, Italy.
Rino
R
Migliacci
Roberto
R
Nasorri
Paolo
P
Ricciarini
Paolo
P
Gresele
D000368:Aged; D000842:Ankle / Q000098:blood supply* / Q000000981:diagnostic imaging; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010173:Palpation / Q000379:methods*; D016491:Peripheral Vascular Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler / Q000379:methods