Systematic review of interventions to reduce delay in patients with suspected heart attack

Objectives: To evaluate the effectiveness of interventions aiming to reduce time from onset of signs and symptoms of an acute myocardial infarction (AMI) to seeking medical help/arrival at hospital.

Methods: A systematic review was conducted. Fifteen electronic databases, the internet, and bibliographies of included studies were searched, and experts in the field of cardiac care were contacted. Randomised controlled trials (RCTs), controlled trials, and before and after studies conducted in any setting that assessed an intervention aimed at reducing time from onset of signs and symptoms of an AMI to seeking medical help and/or arrival in hospital were eligible for inclusion.

Results: Eleven media/public education intervention studies met the inclusion criteria. Five (one controlled and four before and after studies) reported the intervention to have a statistically positive effect on delay time and six (two RCTs and four before and after studies) reported no statistically significant effect. Three (one RCT and two before and after studies) of five studies evaluating the effect of the intervention on emergency department visits reported an increase in this outcome as a result of the intervention, and both studies (one RCT and one before and after study) examining calls made to emergency switchboards reported an increase in this outcome after the intervention.

Conclusions: There was little evidence that media/public education interventions reduced delay. There is some evidence that they may result in an increase in emergency switchboard calls and emergency department visits. Despite substantial expenditure of time and effort, methodological deficiencies of the studies mean that it is not possible to make definitive recommendations.