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PreHospital Ambulance Stroke Test - pilot study of a novel stroke test

Andsberg, Gunnar LU ; Esbjörnsson, Magnus LU ; Olofsson, Arne; Lindgren, Arne LU ; Norrving, Bo LU and Von Euler, Mia (2017) In Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine 25(1).
Abstract

Background: There is a need for a prehospital stroke test that in addition to high sensitivity for stroke, also is able to communicate stroke severity similar to the National Institute of Health Stroke Scale (NIHSS). Methods: The PreHospital Ambulance Stroke Test (PreHAST), an eight item test based on NIHSS, which scores stroke severity from 0-19 points, was designed and adapted for the ambulance services. In the pilot study the ambulance nurses used PreHAST to assess patients with suspected stroke in the prehospital setting. Regardless of the results after PreHAST testing the patients were triaged with a provisional stroke diagnosis. The PreHAST scores were compared with the final diagnosis and the ability to differentiate stroke and... (More)

Background: There is a need for a prehospital stroke test that in addition to high sensitivity for stroke, also is able to communicate stroke severity similar to the National Institute of Health Stroke Scale (NIHSS). Methods: The PreHospital Ambulance Stroke Test (PreHAST), an eight item test based on NIHSS, which scores stroke severity from 0-19 points, was designed and adapted for the ambulance services. In the pilot study the ambulance nurses used PreHAST to assess patients with suspected stroke in the prehospital setting. Regardless of the results after PreHAST testing the patients were triaged with a provisional stroke diagnosis. The PreHAST scores were compared with the final diagnosis and the ability to differentiate stroke and transient ischemic attacks (TIA) with ongoing symptoms at evaluation from non-stroke patients was analysed. Results: 69 patients were included in the study, 26 had stroke/TIA and 43 other diagnoses. All stroke/TIA patients were identified by PreHAST (sensitivity 100% (95% CI; 87-100%)). The specificity increased with higher PreHAST scores and the discriminative capacity for PreHAST for different cut off values showed an area under the curve of 0.77 (95%CI; 0.66-0.88) in the receiver operating characteristic (ROC) analysis. Discussion: PreHAST is designed for high sensitivity, screening for a broad range of stroke symptoms including most key components of NIHSS. The promising sensitivity between 87 and 100% in our study has to be confirmed in a larger study also including multiple centres. Higher PreHAST scores implied more typical patterns of stroke and accordingly the proportion of stroke mimics decrease with higher scores. However, also stroke mimics with epilepsy/seizure and patients with deficit after prior stroke could show higher PreHAST scores. Other prehospital stroke tests that evaluate stroke severity have been designed with the main purpose to screen for large vessel occlusion. The advantage of PreHAST is the dual purpose not only to evaluate stroke severity but also to screen for stroke in general. Conclusions: PreHAST is a new screening test of stroke adapted for ambulance services that in addition to high sensitivity for stroke, provides a grading system with increasing specificity with higher scores.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Cerebrovascular diseases, Prehospital, Stroke Scale, Strokes, TIA, Treatment
in
Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine
volume
25
issue
1
publisher
BioMed Central
external identifiers
  • scopus:85018503719
  • wos:000398727200001
ISSN
1757-7241
DOI
10.1186/s13049-017-0377-x
language
English
LU publication?
yes
id
8da3a764-3ac4-4790-b2f9-956c3a347d55
date added to LUP
2017-05-23 15:17:12
date last changed
2017-09-18 11:37:04
@article{8da3a764-3ac4-4790-b2f9-956c3a347d55,
  abstract     = {<p>Background: There is a need for a prehospital stroke test that in addition to high sensitivity for stroke, also is able to communicate stroke severity similar to the National Institute of Health Stroke Scale (NIHSS). Methods: The PreHospital Ambulance Stroke Test (PreHAST), an eight item test based on NIHSS, which scores stroke severity from 0-19 points, was designed and adapted for the ambulance services. In the pilot study the ambulance nurses used PreHAST to assess patients with suspected stroke in the prehospital setting. Regardless of the results after PreHAST testing the patients were triaged with a provisional stroke diagnosis. The PreHAST scores were compared with the final diagnosis and the ability to differentiate stroke and transient ischemic attacks (TIA) with ongoing symptoms at evaluation from non-stroke patients was analysed. Results: 69 patients were included in the study, 26 had stroke/TIA and 43 other diagnoses. All stroke/TIA patients were identified by PreHAST (sensitivity 100% (95% CI; 87-100%)). The specificity increased with higher PreHAST scores and the discriminative capacity for PreHAST for different cut off values showed an area under the curve of 0.77 (95%CI; 0.66-0.88) in the receiver operating characteristic (ROC) analysis. Discussion: PreHAST is designed for high sensitivity, screening for a broad range of stroke symptoms including most key components of NIHSS. The promising sensitivity between 87 and 100% in our study has to be confirmed in a larger study also including multiple centres. Higher PreHAST scores implied more typical patterns of stroke and accordingly the proportion of stroke mimics decrease with higher scores. However, also stroke mimics with epilepsy/seizure and patients with deficit after prior stroke could show higher PreHAST scores. Other prehospital stroke tests that evaluate stroke severity have been designed with the main purpose to screen for large vessel occlusion. The advantage of PreHAST is the dual purpose not only to evaluate stroke severity but also to screen for stroke in general. Conclusions: PreHAST is a new screening test of stroke adapted for ambulance services that in addition to high sensitivity for stroke, provides a grading system with increasing specificity with higher scores.</p>},
  articleno    = {37},
  author       = {Andsberg, Gunnar and Esbjörnsson, Magnus and Olofsson, Arne and Lindgren, Arne and Norrving, Bo and Von Euler, Mia},
  issn         = {1757-7241},
  keyword      = {Cerebrovascular diseases,Prehospital,Stroke Scale,Strokes,TIA,Treatment},
  language     = {eng},
  month        = {04},
  number       = {1},
  publisher    = {BioMed Central},
  series       = {Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine},
  title        = {PreHospital Ambulance Stroke Test - pilot study of a novel stroke test},
  url          = {http://dx.doi.org/10.1186/s13049-017-0377-x},
  volume       = {25},
  year         = {2017},
}