[Validity of the abdominal ecography in primary care for detection of aorta abdominal aneurism in male between 65 and 75 years].

Objective: To determine the usefulness of ultrasound examination in Primary Care (PC) for the detection of abdominal aortic aneurysm (AAA) in male patients from 65-75 years old, as well as the consistency between observers on the diagnosis between general practitioners and the reference specialty in this area, Vascular Surgery. To estimate the prevalence of AAA in that population and its association with risk factors.

Design: Cross-sectional descriptive study.

Location: Healthcare Centres of Coto and Calzada II (Gijón, Spain).

Participants: Males born between 1 January 1939 and 31 December 1950.

Interventions: From the 2,511 males found, 407 were selected using stratified random sampling. Aortic diameter was measured, with those ≥3cm and 20% from the <3cm being referred for a second measurement by a vascular surgeon.

Variables: Dependent: presence/absence of aneurism. Independent: age, abdominal perimeter, smoking, arterial hypertension, diabetes, dyslipidaemia, familial cases of AAA, cerebrovascular accident, and coronary disease. The analysis was performed using Bayesian inference with models for proportions and a multivariate logistic regression.

Results: From 304 ultrasound scans performed, 13 were referred with suspicion of AAA, and 63 with were within normal. The sensitivity was 93.3% and specificity 98.5% with a 95% credibility interval (CredI) of 75.4-99.9%, and 94.3-100%, respectively. The prevalence was 4.6% (95% CredI: 2.5-7.2%, and the intraclass correlation coefficient between PC and Vascular Surgery was 0.88 (95% CredI: 0.79-0.94). Age, smoking, dyslipidaemia, and diabetes tended to increase the odds of prevalence of AAA.

Conclusion: The ultrasound performed by GPs for the detection of AAA had high diagnostic validity. Further studies on the effectiveness should be conducted in order to assess the appropriateness of introducing a system of early detection of AAA in the risk population.