Development and validation of a screening tool for the identification of inappropriate transthoracic echocardiograms

We sought whether simple clinical markers could be used in a questionnaire for recognition of inappropriate (or rarely appropriate, RA) tests at point-of-service. Most applications of appropriateness criteria (AC) for transthoracic echocardiogram (TTE) have been at the point of order, but a simple means of identifying RA tests in an audit process would be of value.

The study was performed in 2 major hospitals in Tasmania. 2 reviewers created a questionnaire based on 4 questions most commonly associated with RA (suspected endocarditis with no positive blood cultures or new murmur, lack of cardiovascular symptoms or no change in clinical status or cardiac examination, routine surveillance and previous TTE within a year) in a derivation cohort of 814 patients. This was prospectively applied to 499 TTEs to calculate sensitivity and specificity for prediction of RA, and validated in the external group (n=880).

Of 499 prospective TTEs, the questionnaire selected 18% requests as being potentially RA. As 7.4% were actually RA (κ 89%), the sensitivity and specificity of the questionnaire were 84% and 87%, respectively. In the external validation cohort, the model found 11% requests needed to be screened for appropriateness with a sensitivity and specificity of 80% and 95%.

A questionnaire based on 4 questions detects a high proportion of RA TTE, and could be used for audit.