A new scale for assessing patients with vertebrobasilar stroke—the Israeli Vertebrobasilar Stroke Scale (IVBSS): Inter-rater reliability and concurrent validity

Objectives Most of existing stroke scoring systems have limited ability to evaluate patients with cerebrovascular events in the vertebrobasilar territory. We devised a new scale, the Israeli Vertebrobasilar Stroke Scale (IVBSS) in order to directly and more accurately assess clinical deficits of patients with vertebrobasilar stroke. The present study measured the reliability and validity of the IVBSS. Patients and methods Forty-three patients (mean age ± S.D., 70.9 ± 8.8 years, 27 males) with vertebrobasilar stroke were evaluated with the IVBSS (11 items), the NIH Stroke Scale (NIHSS) and the disability modified Rankin Scale (mRS) by independent examiners. Interobserver agreement was rated by weighted kappa statistics for each item and the total IVBSS score. Validity was examined with Spearman rank coefficients to compare the IVBSS with NIHSS and mRS. Results Excellent reliability was demonstrated between the examiners for almost each item and the total score of the IVBSS (kappa > 0.75). The total IVBSS score was strongly associated with NIHSS and mRS results (r = 0.80 and 0.76, respectively; P < 0.0002). Conclusions The IVBSS is a valid instrument that allows the assessment of patients with vertebrobasilar stroke with high reliability. Further observations are warranted to determine the predictive value of the IVBSS for stroke outcome.