Unassisted Assessment of Stroke Severity Using Telemedicine

Abstract

Background and Purpose— Quantification of stroke severity through telemedicine consultation is challenging and relies on professional support at the patient’s bedside. We aimed to develop a novel scale for assessing stroke severity through telemedicine without assistance from a third party (Unassisted TeleStroke Scale [UTSS]). Methods— Stroke severity was assessed in 45 patients with suspicion of acute stroke by bedside examination using the National Institutes of Health Stroke Scale (NIHSS) and by teleconsultation using the UTSS. Scale reliability was evaluated by intrarater and interrater variability, internal consistency, and rater agreement. Concurrent and predictive validity were tested by relating the UTSS with the NIHSS and long-term outcome (modified Rankin Scale and mortality at 6 months). Clinimetric analysis of the UTSS was obtained via the Rasch model. Results— The mean examination time for the UTSS was 3.1 minutes (SD, 1.1) versus 8.5 minutes for the NIHSS (SD, 2.6; P <0.001). Both UTSS and NIHSS showed excellent intrarater variability ( r =0.97 and 0.98; P <0.001) and interrater variability ( r =0.96 and 0.98; P <0.001), as well as excellent internal consistency and rater agreement. The UTSS correlated strongly with the NIHSS and was identified as an independent predictor of stroke outcome in logistic regression analysis. Rasch analysis indicated that the UTSS represents a unidimensional scale of stroke severity. Conclusions— The UTSS is a rapid, reliable, and valid tool for unassisted assessment of stroke severity through telemedicine.