Ankle brachial index measurements in critical leg ischaemia--the influence of experience on reproducibility

Abstract

Background and aims: While the use of ankle brachial indices (ABI) in the screening for peripheral arterial obstructive disease is widely accepted, the applicability of ABI in the identification of critical leg ischaemia (CLI) is far from settled. The aim was to assess inter-observer variability of ABI measurements in patients with CLI.

Material and methods: The study was conducted in two parts. In both parts a hand-held 9.5 MHz Doppler device was used. PART A: ABI was measured by 7 measurers with variable measurement experience in 22 limbs of patients admitted to the surgical ward because of CLI. The agreement between the measurements was assessed. PART B: Inter-observer agreement in measuring ABI was assessed between 2 trained vascular technicians measuring 33 limbs in patients with CLI on the vascular outpatient clinic.

Results and conclusions: Part A: 16% of the ABI-values differed 0.15 or more from the median and the mean coefficient of variation was 56.1. Part B: The difference between measurements did not exceed 0.14 with a mean coefficient of variation of 3.2. To obtain reproducible and quantitative measurement values the measurements have to be performed by trained personnel. Measurements performed by untrained personnel can only be regarded as qualitative.