BACKGROUND: Coronary heart disease (CHD) is the major cause of morbidity and mortality in the UK for both men and women, with acute myocardial infarction (AMI) being the most frequently identified cause of mortality. Thrombolytic therapy in the early hours of an AMI provides considerable risk reduction in terms of damage to the heart and, depending on the agent used, leads to beneficial effects in survival. The effectiveness of thrombolytic therapy is dependent on prompt administration, which has led to increasing attention on the period between the onset of symptoms and treatment. Three different components are involved: patient decision time, transport time, and hospital time from admission to treatment. Patient decision time, defined as the time from onset of signs and symptoms of an AMI to the time when medical assistance is sought, has been found to account for most of this delay. Patient decision time combined with transport time is referred to as pre-hospital delay. The scope for reduction in morbidity and mortality that could result from shortening patient decision time has prompted researchers to investigate what influences patient decision time. Numerous studies have highlighted factors that may be associated with patient decision time, which in turn have prompted the implementation of interventions to improve peoples’ knowledge of the symptoms of AMI and the correct action to take when experiencing such symptoms. OBJECTIVES: To carry out two linked systematic reviews; one to identify the factors associated with patient decision time (referred to as patient delay), and one to evaluate the effectiveness of interventions aiming to reduce patient or pre-hospital delay. In particular, two research questions were addressed: 1) What are the factors that influence the time to seeking medical help following the onset of signs and symptoms of an AMI? 2) How effective are interventions that aim to reduce the time from the onset of signs and symptoms of an AMI to seeking medical help/arrival at hospital?