[Influence of experience on intra- and interindividual variability in assessing peripheral endothelial dysfunction with high resolution ultrasound].
ULTRASCHALL IN DER MEDIZIN (STUTTGART, GERMANY : 1980) 2001;
22:231-235. [PMID:
11607892 DOI:
10.1055/s-2001-17894]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
UNLABELLED
The non-invasive evaluation of endothelial dysfunction with high-resolution ultrasound has become a widely accepted tool in determination of high-risk subjects for early atherosclerosis. Furthermore it is often used as intermediate outcome in intervention studies.
AIM
We examined the influence of examiner experience on intra- and inter-individual variability in the measurement of flow-associated vasodilation (FAD) independent of automated analysis systems.
METHOD
FAD was measured on two occasions in 7 and 8 subjects respectively (mean age 32 +/- 3 years) by two investigators after different prior training procedures with a 13 MHz linear transducer (LA14A, ESAOTE Biomedica).
RESULTS
The intra-individual variability expressed as median absolute difference in the measurements of FAD was 1.1 % (range from 0.03 % to 3.2 %) for examiner one with an experience of more than 50 FAD measurements through former studies and 2.9 % (range from 1.6 % to 9.2 %) for examiner two with only 10 training examinations under supervision. By a further training period of two months, with an increase of examinations of additional 20 measurements by both examiners, the intra-observer variability could be dropped to 0.9 % (range from 0.03 % to 1.3 %) for examiner two (p = 0.0025) with no significant change for examiner one (median 0.6 % with a range from 0.14 % to 3.7 %). As expected, the inter-individual variability was not influenced by this further training (median 1.0 % with a range of 0.5 % to 3.6 % versus a median of 1.6 % with a range from 0.15 % to 7.5 %).
CONCLUSION
30 training measurements of FAD under supervision should be regarded as minimum requirement for valid determination of endothelial function. The reachable result for the intra-observer variability is thereby within the range of computed analysis systems.
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