“Event tree” approach for facilitating audit of ambulance cardiac services

Abstract

An “event” tree technique was used alongside conventional methods for structuring and reporting an audit of ambulance services in Lancashire, UK, for patients with suspected acute myocardial infarction (AMI) and cases of cardiac arrest. The audit covered 4,100 patients attended by ambulance crews. Cross tabulations showed that audit targets were not achieved for recording heart rhythms in non‐arrest cases, administering aspirin and intravenous cannulation. The event tree, linked electronically with the audit database, demonstrated explicitly that only one‐third of non‐arrest patients received all three procedures. With cardiac arrests, the event tree showed that survival rates to hospital were similar for patients in ventricular fibrillation who were defibrillated regardless of whether or not they received anti‐arrhythmic drugs. Interpretation of their performance levels is facilitated by the event‐tree technique that allows relationships between clinical procedures and outcomes of ambulance journeys to be displayed.

Citation

Stoykova, B., Dowie, R., Gregory, R.P.F., Rowsell, K.V. and Lane, S. (2004), "“Event tree” approach for facilitating audit of ambulance cardiac services", Clinical Governance: An International Journal, Vol. 9 No. 2, pp. 115-122. https://doi.org/10.1108/14777270410536402