Sensitivity and specificity of stroke symptom questions to detect stroke or transient ischemic attack

Undiagnosed stroke is a major public health problem. The Questionnaire for Verifying Stroke-Free Status (QVSS) includes eight items and was originally designed to detect stroke-free individuals. Its six symptom-related questions could potentially be used to screen for undiagnosed stroke or transient ischemic attack (TIA), but the sensitivity and specificity of just the six symptom-related questions are unknown.

A research assistant administered the QVSS to outpatients from Veterans Administration stroke and general medicine clinics. Neurologists, blinded to QVSS scores, interviewed and examined all subjects to determine stroke status. Responses to the six symptom questions of the QVSS were compared against the neurologist-determined stroke/TIA status.

The sensitivity of the individual symptom questions ranged from 0.22 to 0.60, and the specificity ranged from 0.79 to 0.95. The sensitivity of any of the six symptom questions was 0.82, and the specificity was 0.62.

The six symptom-related questions of the QVSS demonstrate a high sensitivity and moderate specificity for the diagnosis of stroke or TIA compared with neurological exam. Though these findings should be validated in a more representative general population, these questions have potential for meeting the public health objective of detecting clinically unrecognized but symptomatic stroke.