Prevalence of and Factors Associated with Inappropriate Indications for Transthoracic Echocardiography in Adult Outpatients at Siriraj Hospital

Abstract

Objective: Ordering transthoracic echocardiography (TTE) for inappropriate indications could prolong patient
waiting time, increase echocardiography laboratory workload, and compromise the quality of TTE studies. This
study aimed to investigate the prevalence of and factors associated with inappropriate indications for TTE in adult
outpatients at Siriraj Hospital.
Methods: Two cardiologists prospectively and independently evaluated indications for adult TTE scheduled
during regular office hours at Her Majesty Cardiac Center, Siriraj Hospital. Cases were classified as appropriate,
inappropriate, or uncertain according to the 2011 Appropriate Use Criteria for Echocardiography proposed by a
group of American cardiovascular organizations. Agreement between the two cardiologists was measured using
weighted kappa statistic, and disagreement was resolved by consensus. Factors were evaluated for association with
inappropriate indications for TTE.
Results: Four hundred and eighty-two patients were included. Weighted kappa statistic was 0.46 [95% confidence
interval (CI) 0.34 to 0.59] for agreement between the two cardiologists. Four hundred and thirty-two TTE were
appropriate (89.6%, 95% CI 86.6% to 92.1%), 27 were inappropriate (5.6%, 95% CI 3.9% to 8.0%), and 23 were
uncertain (4.8%, 95% CI 3.2% to 7.0%). Neither status of ordering physician (cardiologist, cardiology fellow, or
cardiothoracic surgeon) nor payment type was found to be significantly associated with the appropriateness of
indications for TTE.
Conclusion: The prevalence of inappropriate indications among adult outpatients undergoing TTE during regular
office hours at Siriraj Hospital was low. No significant association was observed between the appropriateness of
TTE indications and either status of ordering physician or payment type.