The diagnostic accuracy of history taking and physical examination for patients with vertigo in general practice: the VERDI study
Patients with a new episode of vertigo and/or episodic vestibular syndrome in general practice
First, the researchers will perform a systematic review (I) to assess the empirical evidence on diagnostic tests for patients with vertigo in general practice. The most promising tests will be studied during an international Delphi procedure (II) to determine which tests should be investigated in a diagnostic accuracy study (III). During this study, the researchers will compare each index test with its respective reference standard. They will focus on five target conditions that account for more than 95% of vertigo diagnoses in general practice: 1. benign paroxysmal positional vertigo (BPPV), 2. vestibular neuritis, 3. Meniere’s disease, 4. vestibular migraine, and 5. central causes of vertigo. As these five target conditions have a different pathophysiology and all lack a generally accepted reference standard, the researchers will use consensus diagnosis as the reference standard. Data for each patient, including history, physical examination, and additional tests as recommended by international guidelines, will be recorded on a standardized form and independently reviewed by a neurologist and otorhinolaryngologist. For each patient, the reviewers have to decide about the presence/absence of each target condition. The researchers will calculate sensitivity, specificity, predictive values, and likelihood ratios, followed by decision rules for each target condition. Subsequently, they will conduct semi-structured interviews among patients and GPs to investigate barriers and facilitators for the successful implementation of the decision rules. The results of the interviews will be used to construct a final overarching diagnostic algorithm (IV). As clinical decision rules may have a limited effect on physicians, the researchers will perform a comparison study (V) to compare the accuracy of GP judgement with the constructed diagnostic algorithm.
1. Aged 18 years and over 2. New episode of vertigo and/or episodic vestibular syndrome (definition: see below) 3. Presentation of symptoms during (telephone) consultation or home visit Definition of vertigo: The VERDI study will adopt the nomenclature of the Bárány society, the leading international organization for clinicians and researchers involved in vestibular medicine. The Bárány society previously realized the International Classification of Vestibular Disorders (ICVD), a uniform way to describe vestibular symptoms. The VERDI study will focus on patients with vertigo (defined by the ICVD as “the sensation of self-motion when no self-motion is occurring or the sensation of distorted self-motion during an otherwise normal head movement”) and/or episodic vestibular syndrome (defined by the ICVD as “clinical syndrome of transient vertigo, dizziness, or unsteadiness lasting seconds to hours, occasionally days, and generally including features suggestive of temporary, short-lived vestibular system dysfunction”). When assessing a patient with vestibular symptoms, the Bárány society recommends focusing on timing (onset, duration, and evolution of symptom) and triggers (actions, movements, or situations that provoke the onset of symptoms. During the diagnostic accuracy study, the researchers will investigate the diagnostic value of timing, triggers, and other (individual and combinations of) items of history taking.
1. Serious comorbid conditions that preclude participation in the VERDI study (judgement of patient’s GP) 2. Severe cognitive impairment (judgement of patient’s GP) 3. Insufficient mastery of Dutch and English language