Appropriateness criteria in the request for carotid ultrasonography. A multicentre study

The objective of this study was to analyse appropriateness criteria in the request for carotid ultrasonography and to evaluate its association with the finding of a significative carotid stenosis.

This was an observational, prospective, analytical, multicentre study. Consecutive adult patients (>18years of age) who were scheduled for carotid ultrasound were included. Carotid ultrasound requests were made by the various departments of the participating hospitals and by primary care. Urgent indications were excluded. The reasons for the request and the results of the examinations were recorded. Appropriateness criteria of carotid ultrasonography were determined taking into account recommendations from the literature and clinical practice guidelines. A bivariate and multivariate analysis were performed to determine patient factors related to the appropriateness of requests.

A total of 268 patients were included, with a mean age of 69.1 (SD12) years, 34.3% women. Most requests were classified as adequate (65.3%; 95%CI: 59.3-71.0), while the percentage of inadequate requests, according to previously established criteria, was 31.7% (95%CI: 26.2-37.7). The prevalence of significant stenosis in inappropriate requests was very low (1.2%). In the bivariate analysis, the factors associated with significant carotid stenosis (≥50%) were age, high blood pressure, and dyslipidaemia. When all three variables were included in the multivariate model, only dyslipidaemia was significant: OR: 5.47 (95%CI: 2.7-11.0).

32% of carotid ultrasonography requests were inappropriate, with a very low prevalence.