Reproducibility and reliability of the ankle—brachial index as assessed by vascular experts, family physicians and nurses

• Published in: Vascular medicine (London, England) England), 2007-05, Vol.12 (2), p.105-112
• Main Authors: Holland-Letz, Tim, Endres, Heinz G., Biedermann, Stefanie, Mahn, Matthias, Kunert, Joachim, Groh, Sabine, Pittrow, David, von Bilderling, Peter, Sternitzky, Reinhardt, Diehm, Curt
• Format: Article
• Language: English
• Subjects: Aged; Analysis of Variance; Ankle - blood supply; Ankle - diagnostic imaging; Biological and medical sciences; Blood and lymphatic vessels; Blood Pressure; Brachial Artery - diagnostic imaging; Brachial Artery - physiopathology; Cardiology. Vascular system; Cardiovascular system; Diseases of the cardiovascular system; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Female; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Mass Screening - methods; Medical sciences; Medicine; Nurses; Observer Variation; Peripheral Vascular Diseases - diagnostic imaging; Peripheral Vascular Diseases - physiopathology; Physicians, Family; Predictive Value of Tests; Radionuclide investigations; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Regional Blood Flow; Reproducibility of Results; Specialization; Ultrasonography
• ISSN: 1358-863X; 1477-0377
• DOI: 10.1177/1358863X07077281

The reliability of ankle—brachial index (ABI) measurements performed by different observer groups in primary care has not yet been determined. The aims of the study were to provide precise estimates for all effects influencing the variability of the ABI (patients' individual variability, intra- and inter-observer variability), with particular focus on the performance of different observer groups. Using a partially balanced incomplete block design, 144 unselected individuals aged ≥ 65 years underwent double ABI measurements by one vascular surgeon or vascular physician, one family physician and one nurse with training in Doppler sonography. Three groups comprising a total of 108 individuals were analyzed (only two with ABI < 0.90). Errors for two repeated measurements for all three observer groups did not differ (experts 8.5%, family physicians 7.7%, and nurses 7.5%, p = 0.39). There was no relevant bias among observer groups. Intra-observer variability expressed as standard deviation divided by the mean was 8%, and inter-observer variability was 9%. In conclusion, reproducibility of the ABI measurement was good in this cohort of elderly patients who almost all had values in the normal range. The mean error of 8—9% within or between observers is smaller than with established screening measures. Since there were no differences among observers with different training backgrounds, our study confirms the appropriateness of ABI assessment for screening peripheral arterial disease (PAD) and generalized atherosclerosis in the primary case setting. Given the importance of the early detection and management of PAD, this diagnostic tool should be used routinely as a standard for PAD screening. Additional studies will be required to confirm our observations in patients with PAD of various severities.