Background: Faster treatment with tPA may be achieved by optimizing prehospital triage with mobile stroke units (MSUs). The Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit (BEST-MSU) study is a prospective comparative effectiveness trial of outcomes in patients randomized to MSU or standard management (SM).
Purpose: To evaluate the inter-rater agreement for tPA eligibility between a telemedicine vascular neurologist (TM-VN) and the onboard vascular neurologist (OB-VN) in acute stroke patients seen on the MSU.
Methods: Cluster randomization of MSU and SM weeks started on August 18, 2014. On scene, both the TM-VN and OB-VN evaluated the patient and independently documented their tPA treatment decision, NIHSS and CT interpretation. Agreement was determined using Cohen’s kappa (K) statistic. TM related technical failures that impeded remote assessment were recorded.
Results: The remote TM-VN evaluated 173 patients. In 4 (2%) cases the TM-VN was not able to make a decision about tPA because of technical difficulties ( 1 case due to TM camera failure and 3 cases due to poor connectivity). The TM-VN agreed with the OB-VN on 88% of evaluations, with a K of 0.73 representing substantial agreement. Baseline NIHSS correlation between the TM-VN and OB-VN was 0.88. Agreement about ICH on CTH was a near-perfect K of 0.97.
Conclusions: We conclude from these results that remote VN assessment of stroke patients in the MSU via TM is clinically and technologically feasible, reliable and accurate. TM assessment of CTH and NIHSS was also comparable to the OB evaluation. These findings will allow either OB-VN or TM-VN assessment for the remainder of the study.