Validating the Client Oriented Scale of Improvement for Dizziness and Imbalance (COSIDI)

Measuring vestibular rehabilitation progress with questionnaires can be difficult in time-limited clinical settings. We developed and tested a new brief tool: Client Oriented Scale of Improvement for Dizziness and Imbalance (COSIDI), based on validated client-oriented scales for hearing aids (COSI) and for tinnitus (COSIT), and on wider evidence for involving patients in specifying the goals for rehabilitation. We developed the COSIDI with patient and clinician feedback and validated it through comparison with Dizziness Handicap Inventory (DHI) and Vestibular Rehabilitation Benefit Questionnaire (VRBQ) during normal clinical appointments. 91 outpatients in three clinical settings in Cardiff, Swansea and Southampton. COSIDI improvement scores showed comparable effect size with DHI and VRBQ (Cohen’s d = 1.1 vs 1.2 and 0.64) and correlated highly with the existing measures (r = 0.73). Clinicians found COSIDI to be useful and appropriate for rehabilitation measurement, due to its patient-focus, brevity and support for goal-setting. COSIDI is a valid tool for assessing vestibular rehabilitation, used alone or as complementary to other tools, which clinicians indicated provide useful prompts for patients to consider.