The Psychometric Properties of the 9-Item Vestibular Activities Avoidance Instrument.

Abstract

The purpose of this study was to establish the psychometric properties of the 9-Item Vestibular Activities Avoidance Instrument (VAAI-9), a patient-reported outcome measure developed to identify fear avoidance beliefs in persons with vestibular disorders. This prospective cohort study included 100 participants 18years and older seeking care at a balance disorders clinic for dizziness. Participants completed the VAAI-9, the Dizziness Handicap Inventory (DHI), and other patient-reported outcomes at the initial visit and the 3-month follow-up. To measure test-retest reliability, the VAAI-9 was completed again 5days after the initial visit and was analyzed using a 2-way mixed ICC for absolute agreement. Internal consistency was determined using the Cronbach alpha. The Spearman correlation coefficient was used to assess convergent validity of the VAAI-9 with other outcomes. Receiver operating characteristic curves were used to identify baseline VAAI-9 cutoff scores for those who reported mild (DHI ≤ 30) or moderate or severe (DHI > 30) perceived disability at the 3-month follow-up. The mean age of the study cohort was 49 (SD = 16) years; 73 (73%) were women. Seventy-one participants completed the 5-day follow-up, and 68 completed the 3-month follow-up. The VAAI-9 demonstrated excellent internal consistency (α = 0.91) and test-retest reliability (ICC = 0.90). Baseline VAAI-9 scores had moderate to strong associations with other outcome measures at baseline and 3months. A baseline VAAI-9 score of 26 or higher had a sensitivity of 80.6% and a specificity of 78.4% for identifying a DHI score of >30 at 3months (area under the curve = 0.86). The results provide evidence of excellent reliability and validity for the 9-item VAAI in persons with vestibular disorders. A baseline VAAI-9 score of ≥26 identified individuals at risk of persistent moderate to severe disability due to dizziness. Initial levels of fear avoidance beliefs measured using the VAAI-9 provided important prognostic information about outcomes for persons with vestibular symptoms.