Objectives: Identify highrisk clinical characteristics for a serious cause of vertigo in patients presenting to the emergency department. Design: Multicentre prospective cohort study over 3 years. Setting: Three university affiliated tertiary care emergency departments. Participants: Patients presenting with vertigo, dizziness or imbalance. A total of 2078 of 2618 potentially eligible patients (79.4%) were enrolled (mean age 77.1 years; 59% women). Main outcome measurements: An adjudicated serious diagnosis defined as stroke, transient ischemic attack, vertebral artery dissection or brain tumour. Results: Serious events occurred in 111 (5.3%) patients. We used logistic regression to create a 7 item prediction model: male, age over 65, hypertension, diabetes, motor/sensory deficits, cerebellar signs/symptoms and benign paroxysmal positional vertigo diagnosis (C statistic 0.96, 95% confidence interval [CI] 0.92 0.98). The risk of a serious diagnosis ranged from 0% for a score of <5, 2.1% for a score of 5-8, and 41% for a score >8. Sensitivity for a serious diagnosis was 100% (95% CI, 97.1 100%) and specificity 72.1% (95% CI, 70.1 74%) for a score <5. Conclusions: The Sudbury Vertigo Risk Score identifies the risk of a serious diagnosis as a cause of a patient's vertigo and can assist physicians in guiding further investigation, consultation and treatment decisions, improving resource utilization and reducing missed diagnoses.

The authors have declared no competing interest.

Physician Services Incorporated, NOAMA

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