Acute Video-oculography for Vertigo in Emergency Rooms for Rapid Triage (AVERT)

Study Overview
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Brief Summary
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AVERT is a randomized controlled trial comparing video-oculography (VOG)-guided care to standard care to assess accuracy of diagnoses and initial management decisions for emergency department (ED) patients with a chief symptom of vertigo or dizziness suspected to be of vestibular cause. The trial will test the hypothesis that VOG-guided rapid triage (VRT) will accurately, safely, and efficiently differentiate peripheral from central vestibular disorders in ED patients presenting acute vertigo or dizziness, and that doing so has the potential to improve post-treatment clinical outcomes for these patients.

Detailed Description
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AVERT is a multicenter, Phase II clinical trial comparing a novel diagnostic strategy (VRT) to standard ED diagnostic care at three performance sites. The Specific Aims are to assess diagnostic accuracy, diagnostic workup costs, and estimate the short-term impact of correct diagnosis in anticipation of a larger, definitive Phase III trial. Adult ED patients with a chief symptom of vertigo, dizziness, or unsteadiness, new or clearly worse in the previous 30 days, will undergo on-site vestibular function tests by trained research personnel using a portable, quantitative VOG recording device. Research personnel will also record a focused symptom history and bedside hearing tests. Eligible patients with at least one pathologic vestibular eye movement finding or pathologic ataxia will be randomized to VRT or standard ED care. Patients eligible for pre-randomization testing but excluded from randomization will be slated for the Observational Arm of the study and will undergo limited 1 and 6 month phone follow-up. The VRT arm relies on an automated algorithm to interpret VOG results, thereby determining a patient-specific clinical care pathway. For safety, all VRT-arm study subjects will undergo stroke protocol MRI before release. All randomized subjects will undergo confirmatory testing at one week, including vestibular specialist exam and 1.5 or 3-Tesla research MRI combining stroke and internal auditory canal protocols. All randomized patients will also undergo 1 month and 6 month phone follow-up and medical record review to confirm diagnoses. Clinical findings, ED diagnoses, diagnostic resource utilization, treatments applied, and clinical events during follow-up will be recorded. A multidisciplinary, masked, expert panel will adjudicate final diagnoses.

Official Title
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Acute Video-oculography for Vertigo in Emergency Rooms for Rapid Triage (AVERT)

Conditions
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Vertigo, Dizziness

Intervention / Treatment
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* Device: VRT Care


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Adult (18 years and older) ED patients with all of the following (all determined pre-randomization): VESTIBULAR SYMPTOMS: presenting symptom of vertigo OR dizziness OR unsteadiness (as defined by consensus expert definitions in the International Classification of Vestibular Disorders). RELEVANT EXAM SIGNS*: pathologic nystagmus (spontaneous, gaze-evoked, or positional) by bedside VOG testing OR pathologic ataxia (gait, trunk, stance, limbs) by bedside ataxia examination. RECENT ONSET: symptoms AND signs* appear to be new or markedly worse in the past month * Exam signs are required for randomization, but not for the observational arm Exclusion Criteria Excluded from Pre-Randomization Screening Level 1 trauma or critical illness Altered mental status (e.g., delirium, dementia) that would preclude active study participation (this includes patients with abnormal mental state due to alcohol intoxication or illicit substance, which are known, easily-recognized causes of dizziness or vertigo presentations to the ED) Non-English speaking (enrollment of non-English speakers is not feasible given the logistics of identifying a translator and the need for rapid recruitment and randomization in the AVERT study; furthermore, the terms vertigo, dizziness, and unsteadiness may have different meanings in other languages) Known pregnancy (all women of childbearing age who are enrolled will undergo a urine or serum beta-HCG pregnancy test prior to MRI to confirm no pregnancy, per local institutional guidelines) Unable or unsafe to participate in screening, including VOG tests (as deemed by specific pre-enrollment risk assessment questions or ED provider and/or Study Coordinator judgment) including, but not limited to: visual impairment sufficient to prevent visual fixation during the VOG testing clinically-perceived risk to patient of participating in study (ED provider or staff concerns) clinically-perceived risk to research staff (e.g., violence, blood/body fluid/respiratory precautions) unstable cardiac status (given a single reported case of bradycardia with impulse testing) acute cranio-cervical trauma or other condition (e.g., rheumatoid arthritis) that might lead to instability of the cervical spine that would be a contraindication to neck rotation during VOG testing Obvious general medical cause (as judged by treating ED provider) including, but not limited to, acute myocardial infarction, pulmonary embolus, pneumonia, urinary tract infection, drug intoxication, etc. Excluded from Randomization (Eligible for Observational Arm Follow-up) Patient previously randomized in the AVERT Trial (previously screened but not randomized are eligible) Unable to participate fully with study follow-up (particularly MRI) including, but not limited to: unable to return for follow-up testing within 30 days unable to undergo MRI because of contraindications (e.g., pacemaker, metallic foreign body, pregnancy) or other reasons (severe claustrophobia, too large or too heavy for MRI scanner)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: VRT Care<br>Patients randomized to VRT (VOG-guided Rapid Triage) care will have an algorithm-determined patient-specific diagnosis and treatment pathway in the emergency department. Patients will complete a 1 week in-person follow up and a 1 and 6 month phone follow up. | Device: VRT Care<br>* The VOG report includes direct device output (physiologic traces, quantitative measures) plus most likely diagnosis, category, and clinical trial care pathway (peripheral, equivocal, central) instructions. The VOG report becomes part of the patient's emergency department clinical record.<br>* Other names: GN Otometrics (Instrumentation & Control Systems, Inc);|
| No Intervention: Standard of Care (SOC)<br>Patients randomized to Standard of Care will undergo usual emergency department care without revealing results of VOG testing. Patients will complete a 1 week in-person follow up and a 1 and 6 month phone follow up. | |
| No Intervention: Observational<br>Patients who signed an informed consent but did not meet inclusion/exclusion criteria and don't randomize will enter a parallel track observational sub-study with limited 1 and 6 month phone follow-up. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Six-Category Diagnosis Accuracy (all, VRT vs. SOC) | Total diagnosis accuracy VRT vs. SOC using 30-day adjudicated final diagnoses categorized in one of six possible diagnosis categories (3 peripheral, 1 central, 1 medical/other, 1 non-diagnosis). We will use Index VRT Diagnosis and ED Physician Diagnosis compared to the Adjudicated Final Diagnosis based on ED index visit and 30-day follow-up clinical assessments. Also analyzed for each diagnosis category will be sensitivity, specificity, predictive values, likelihood ratios. | 6 months after last patient/last visit | 
| Index Visit Total Diagnostic Utilization Costs (all, VRT vs. SOC) | Total dollar costs VRT vs. SOC for diagnostic tests and consultations obtained during the ED index visit and hospital admission (for those admitted at the index visit). For the VRT arm, this does not include costs of protocol safety MRIs or any tests ordered off-protocol by ED physicians. It does include tests ordered on-protocol by consultants or ED physicians in the VRT 'equivocal' pathway. Total costs will be calculated by multiplying fixed cost estimates (most recent year available average Medicare reimbursement in US dollars) by utilization rates for each ED index visit service tracked. | 6 months after last patient/last visit | 
| Odds of Short-Term Serious Medical Events (SMEs) after Misdiagnosis (SOC arm only, correct vs. incorrect diagnoses) | We will use 30-day adjudicated final diagnoses categorized in one of six possible categories to determine correct vs. incorrect diagnoses. We will consider SMEs occurring between the time of ED index visit disposition and 1-week research follow-up visit. Events diagnosed at the ED index visit will not be counted. Events newly diagnosed at the 1-week follow-up or in the interval prior to follow-up will be counted, regardless of their relatedness to the ED index dizziness symptoms, with the exception of test or treatment complications. Diagnostic test or treatment complications must be related directly or indirectly to the dizziness symptoms. To avoid 'double counting' misdiagnoses as SMEs that are pursuant to misdiagnosis, 1-week stroke diagnoses not rendered at the ED index visit will not be counted as SMEs unless neurologic or vestibular symptoms/signs worsen after ED index discharge. | 9 months after last patient/last visit | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Expert VOG Six-Category Diagnosis Accuracy (all, expert VOG vs. SOC) | Total diagnosis accuracy adjudicated expert VOG diagnosis vs. SOC using 30-day adjudicated final diagnoses categorized in one of six possible diagnosis categories (3 peripheral, 1 central, 1 medical/other, 1 non-diagnosis). We will use Index VOG Diagnosis and ED Physician Diagnosis compared to the Adjudicated Final Diagnosis based on ED index visit and 30-day follow-up clinical assessments. This outcome measure reflects the theoretical maximum diagnostic accuracy performance (i.e., expert level) of any future algorithms. | 6 months after last patient/last visit | 
| Stroke-No Stroke Diagnosis Accuracy (all, VRT vs. SOC) | Total diagnosis accuracy VRT vs. SOC using 30-day adjudicated final diagnoses categorized as stroke vs. no stroke (posterior fossa mass lesion, encephalitis, etc.). Also analyzed for the stroke diagnosis category will be sensitivity, specificity, predictive values, likelihood ratios. | 6 months after last patient/last visit | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Vertigo, Dizziness, Unsteadiness, Stroke, Vestibular neuritis, Benign paroxysmal positional vertigo, Vestibulo-ocular reflex, Video-oculography, Emergency department