The Prehospital Stroke Score and telephone conference: A prospective validation

Objectives: The main aim of the study is to investigate the performance of a two-part stroke scale for screening and subsequent severity assessment combined with a telephone conference (teleconference).

Materials and methods: During a 6-month period, we prospectively tested the Prehospital Stroke Score (PreSS). PreSS part 1 is designed to identify stroke or TIA in a prehospital setting. PreSS part 2 is a stroke severity scale designed to identify large-vessel occlusion (LVO). PreSS was performed by emergency medical service (EMS) providers prior to a teleconference with a stroke neurologist.

Results: Combined teleconference and PreSS part 1 were performed on 79.3% of all patients diagnosed with stroke/TIA, and 99.1% of the patients with positive scores were subsequently PreSS part 2 scored. PreSS part 1 and teleconference had a sensitivity to identify stroke/TIA of 89.3% (95% CI 85.7-92.2), specificity of 64.5% (95% CI 59.3-69.5), and an area under the curve (AUC) of 0.80 (95% CI 0.77-0.83). Regarding LVO, PreSS part 1 with teleconference recognized 96.7% (95% CI 88.7-99.6) of all cases as stroke. PreSS part 2 had a sensitivity of 55.7% (95% CI 42.4-68.5), specificity of 91.5% (95% CI 89.0-93.6), and AUC of 0.86 (95% CI 0.82-0.90) for identification of LVO.

Conclusions: PreSS was feasible and the sensitivity for stroke/TIA and LVO was high to moderate providing an overall high precision. Almost all LVO cases were ensured acute stroke admission. The high specificity for LVO could be useful for determining transfers strategies.

Classification of evidence: This study provides Class I evidence when evaluating PreSS combined with teleconference.