Abstract
BACKGROUND: The usefulness of prehospital scales for identifying anterior circulation large vessel occlusion (aLVO) in patients with suspected stroke may vary depending on the severity of their presentation. The performance of these scales across the spectrum of deficit severity is unclear. The aim of this study was to evaluate the diagnostic performance of 8 prehospital scales for identifying aLVO across the spectrum of deficit severity. METHODS: We used data from the PRESTO study (Prehospital Triage of Patients With Suspected Stroke Symptoms), a prospective observational study comparing prehospital stroke scales in detecting aLVO in suspected stroke patients. We used the National Institutes of Health Stroke Scale (NIHSS) score, assessed in-hospital, as a proxy for the Clinical Global Impression of stroke severity during prehospital assessment by paramedics. We calculated the sensitivity, specificity, positive predictive value, negative predictive value, and the difference in aLVO probabilities with a positive or negative prehospital scale test (ΔPaLVO) for each scale for mild (NIHSS 0-4), intermediate (NIHSS 5-9), moderate (NIHSS 10-14), and severe deficits (NIHSS≥15). RESULTS: Among 1033 patients with suspected stroke, 119 (11.5%) had an aLVO, of whom 19 (16.0%) had mild, 25 (21.0%) had intermediate, 30 (25.2%) had moderate, and 45 (37.8%) had severe deficits. The scales had low sensitivity and positive predictive value in patients with mild-intermediate deficits, and poor specificity, negative predictive value, and accuracy with moderate-severe deficits. Positive results achieved the highest ΔPaLVO in patients with mild deficits. Negative results achieved the highest ΔPaLVO with severe deficits, but the probability of aLVO with a negative result in the severe range was higher than with a positive test in the mild range. CONCLUSIONS: Commonly-used prehospital stroke scales show variable performance across the range of deficit severity. Probability of aLVO remains high with a negative test in severely affected patients. Studies reporting prehospital stroke scale performance should be appraised in the context of the NIHSS distribution of their samples.
| Original language | English |
|---|---|
| Pages (from-to) | 3605-3615 |
| Number of pages | 11 |
| Journal | Stroke |
| Volume | 53 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Dec 2022 |
Bibliographical note
Funding Information:Dr Ganesh reports membership in the editorial board of Stroke; consulting fees from Atheneum, MD Analytics, MyMedicalPanel, Figure1, Creative Research Designs, and CTC Communications Corp; research support from Alberta Innovates, Campus Alberta Neuroscience, the Canadian Cardiovascular Society, the Sunnybrook Research Institute INOVAIT program, and the Canadian Institutes of Health Research; stock/stock options from SnapDx and TheRounds com; and a patent application for a system for prehospital patient monitoring/assessment, remote ischemic conditioning, and other cuff based therapies Drs Dippel and van der Lugt, report funding from the Dutch Heart Foundation, Brain Foundation Netherlands, The Netherlands Organisation for Health Research And Development, Health Holland Top Sector Life Sciences & Health, and unrestricted research grants from Penumbra, Stryker, Medtronic, Thrombolytic Science, and Cerenovus Dr Goyal reports consulting fees from Medtronic, Stryker, Microvention, and Mentice; and has a patent for Systems of stroke diagnosis licensed to GE Healthcare All other authors have nothing to disclose.
Funding Information:
PRESTO was funded by the BeterKeten Collaboration and Theia Foundation (Zilveren Kruis). The funders had no role in study design, data collection, data analysis, data interpretation, or writing of the report, or the decision to submit for Publication.
Publisher Copyright:
© 2022 American Heart Association, Inc.