Medical dispatchers recognise substantial amount of acute stroke during emergency calls

Søren Viereck, Thea Palsgaard Møller, Helle Klingenberg Iversen, Hanne Christensen, Freddy Lippert

Immediate recognition of stroke symptoms is crucial to ensure timely access to revascularisation therapy. Medical dispatchers ensure fast admission to stroke facilities by prioritising the appropriate medical response. Data on medical dispatchers' ability to recognise symptoms of acute stroke are therefore critical in organising emergency stroke care. We aimed to describe the sensitivity and positive predictive value of medical dispatchers' ability to recognise acute stroke during emergency calls, and to identify factors associated with recognition. This was an observational study of 2653 consecutive unselected patients with a final diagnosis of stroke or transient ischemic attack (TIA). All admitted through the Emergency Medical Services Copenhagen, during a 2-year study period (2012-2014). Final diagnoses were matched with dispatch codes from the Emergency Medical Dispatch Centre. Sensitivity and positive predictive value were calculated. The effect of age, gender, and time-of-day was analysed using multivariable logistic regression. The sensitivity was 66.2 % (95 % CI: 64.4 %-68.0 %), and the positive predictive value was 30.2 % (95 % CI: 29.1 %-31.4 %). The multivariable logistic regression analyses showed that emergency calls during daytime and a final diagnosis of TIA vs. intracerebral haemorrhage (ICH), was positively associated with recognition of stroke (OR 2.70, 95 % CI: 2.04-3.57). This study reports a high rate of stroke recognition compared to other studies ranging from 31% to 74%. The high sensitivity is likely the result of a profound reorganisation of the Emergency Medical ServicesCopenhagen, including the introduction of EMDs with a medical profession, and a criteria-based dispatch tool. A recognition rate of 100 % is not obtainable without an inappropriate amount of false positive cases. We report an overall high recognition of stroke by medical dispatchers. A final diagnosis of TIA, compared to ICH, was positively associated with recognition of acute stroke. Emergency medical dispatchers serve as the essential first step in ensuring fast-track stroke treatment, which would promote timely acute therapy. Unique identifier: NCT02191514 .