Each year, over 15 million people attend an emergency department in England and Wales.1 It has been estimated that 2.4% of attendances are because of chest pain,2 representing 360 000 emergency department attendances. Despite this, surprisingly little data have been published describing this problem. Studies typically report selected groups of patients, or retrospective audits of routinely collected data. Both approaches may lead to biased results. Accurate estimates of the size and nature of the problem are required to allow rational planning of services and to put the findings of research into context.
The ESCAPE (effectiveness and safety of chest pain assessment to prevent emergency admissions) randomised controlled trial of chest pain observation unit versus routine care3 required prospective identification of all patients attending with acute chest pain; it thus provided an ideal opportunity for a descriptive study of the health care burden created by this problem. We aimed to describe the clinical epidemiology of acute chest pain, the incidence of emergency department presentation and hospital admission, the proportion with ECG evidence of acute coronary syndrome (ACS), clinically diagnosed ACS, non-ACS, or undifferentiated chest pain, and variations in these parameters by hour of day and day of week.