“…Ongoing studies have demonstrated mixed results, with some demonstrating positive associations between type A behaviour and coronary heart disease risk [13] and acute myocardial infarction (AMI) [14], and others reporting no correlation between type A behaviour and abnormalities in sympathetic or cardiovascular reactivity [15], myocardial infarction, or 10-year prognosis after myocardial infarction [16,17]. A meta-analysis of research in this area identified that null findings were due to range-restriction biases, where only diseased people were selected for study, self-report measures of type A behaviour, which were more likely to produce null findings, and finally the use of myocardial infarction as the disease criterion.…”