Nor AM et al. (2005) The recognition of stroke in the emergency room (ROSIER) scale: development and validation of a stroke recognition instrument. Lancet Neurol 4: 727–734

In view of the fact that many patients with stroke present to the emergency room, recognition of the signs and symptoms of stroke by emergency-room physicians is crucial if early intervention is to be achieved. A UK group has developed a new stroke recognition tool for use in this setting, which promises to improve the differentiation of acute stroke from other conditions.

The design of the instrument—termed the Recognition of Stroke in the Emergency Room (ROSIER) scale—began with a 1-year developmental phase, involving 343 adult referrals from the emergency room to the acute stroke team. By recording the clinical characteristics of the patients with confirmed stroke or transient ischemic attack (n = 176) and those without stroke (n = 167), the researchers developed a seven-item stroke recognition tool. This tool covered loss of consciousness or syncope, seizures, asymmetric weakness of the face, arm or leg, and problems with speech or the visual field. Using a simple proforma to generate a 'ROSIER score', the instrument could then be used to determine the likelihood of stroke.

Following an internal validation process, the team carried out a 9-month prospective validation of the instrument. During this period, the proportion of non-stroke cases referred from the emergency room fell significantly. The ROSIER instrument “has good diagnostic accuracy and is simple to administer,” say the researchers, and might be useful in the early recognition of stroke by emergency-room staff.