Beyond clinical trials: Translation of evidence into practice in the treatment of acute myocardial infarction.

The impact of clinical trials on routine medical practice is the fundamental issue under investigation. Acute myocardial infarction (AMI) was chosen for study because of its public health importance and the weight of evidence to guide the use of thrombolytics, aspirin and beta blockers. At the start of this research little was known of the extent of use of these agents and the factors associated with their utilisation in routine care. An observational design, combining research methods derived from epidemiology, was utilised to study the treatment of 4,035 representative AMI patients admitted to hospital in Europe. Patient samples were drawn as consecutive or random samples from representative regions in the United Kingdom and ten other European countries between January 1993 and June 1994. Data on acute treatment were collected retrospectively from medical notes. Information on long-term therapy was obtained mainly by direct contact with the patient at 6 months after AMI. A substantial apparent under-use of thrombolytic agents and long-term beta blockers (but not aspirin or other antithrombotic agents) was identified. Factors associated with a significantly decreased likelihood of receiving treatment with these agents included older age and female sex. In addition, there was wide variation between regions in the extent of use of the pharmacotherapies under study. Characterisation of the AMI patient population admitted to hospital identified significant differences from the clinical trials' population. It appears that selective patient recruitment into clinical trials has limited the generalisability of the results to the clinical AMI population and may have contributed to the observed variation in prescribing practice. Methods to aid the translation of clinical trials results into routine practice are discussed and the need for research to identify effective mechanisms is highlighted. An implementation strategy for the treatment of AMI is proposed with the aim of routine provision of evidence based care for all AMI patients.