Understanding the patient’s history and interpreting the clinical examination can be challenging in emergencies. Although the immediate presenting problem may be clear—“I’ve hurt my hand” or “I have a cough”—confounding factors such as pain and anxiety may obfuscate the symptoms and mask the signs. In these circumstances a rational approach to clinical assessment is essential.1

The Ottawa ankle rules are probably the most well known and frequently used clinical decision support rules for use in emergencies.2 3 Evidence based approaches have, however, been developed to help in many other emergency situations, including head injury in adults and children,4 5 neck injury,6 knee injury,7 mandibular trauma,8 and risk assessment after self harm.9

In the linked study (doi:10.1136/bmj.a2428), Appelboam and colleagues extend this work with the results of the SWEET study—a multicentre prospective diagnostic cohort study that investigates a simple clinical test (extension of the …