Aim. To evaluate the diagnostic accuracy of the STANDING algorithm across different emergency departments (ED)s. As secondary outcomes we compared the STANDING and the local usual care (LUC), in term of accuracy, use of diagnostic resources and length of stay (LOS). Methods. We prospectively enrolled adult patients presenting with vertigo/dizziness at one 'hub' and three 'spoke' EDs in Tuscany, evaluated using either STANDING or LUC depending on the availability of a trained emergency physician (EP). Imaging tests, consultations and discharge/admission decisions were made independently of the study. The reference standard was a diffusion-weighted MRI of the brain and 30-days follow-up. Results. We included 456 patients, 242 (53%) assessed by STANDING. No difference in age, gender and prevalence of cardiovascular risk factors were present between STANDING and LUC groups. The prevalence of central vertigo was 8.6%, with ischemic stroke (4.2%) as the leading cause, without differences between the two groups. The sensitivity, specificity, positive and negative predictive values (95% CI) of STANDING for central disease were 88.2% (63.6-98.5), 91.6% (87.1-94.8), 44.1% (33.2-55.7), 99% (96.5-99.7), without differences between the ?hub? and the ?spoke? centres and when only ischemic stroke was considered. STANDING demonstrated higher specificity and positive predictive values than that of LUC (36.5% and 14.7%, p<0.05 for both). Additionally, requests for head CT were lower (48.3% vs. 66.8%) and LOS shorter (289 vs. 351 minutes) in the STANDING group (p<0.05 for both). Conclusions. The STANDING algorithm showed a good accuracy and a very high negative predictive value for excluding central disease and stroke, across different EDs. Compared to LUC, STANDING showed increased specificity, reduced utilisation of head CT and a shorter LOS.

The authors have declared no competing interest.

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Comitato per l'etica nella clinica Azienda USL Toscana centro

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Dear Editor, all data analyzed during this study are included in the manuscript. Additional datasets supporting the findings of this study are available from the corresponding author upon reasonable request. Sincerely, Dr Mattia Ronchetti