Systematic review of patient-reported outcome measures in clinical vestibular research

Objective: To identify the most commonly used patient-reported outcome (PRO) measures in clinical vestibular research, and to assess their test characteristics and applicability to the study of age-related vestibular loss in clinical trials.

Data sources: We performed a systematic review of the PubMed, Cumulative Index to Nursing and Allied Health Literature, and PsycINFO databases from 1950 to August 13, 2013.

Study selection: PRO measures were defined as outcomes that capture the subjective experience of the patient (eg, symptoms, functional status, health perceptions, quality of life). Two independent reviewers selected studies that used PRO measures in clinical vestibular research. Disparities were resolved with consensus between the reviewers. Of 2260 articles initially found in the literature search, 255 full-text articles were retrieved for assessment. Of these, 104 met inclusion criteria for data collection.

Data extraction: PRO measures were identified by 2 independent reviewers. The 4 most commonly used PROs were evaluated for their applicability to the condition of age-related vestibular loss. Specifically, for these 4 PROs, data were collected pertaining to instrument test-retest reliability, item domains, and target population of the instrument.

Data synthesis: A total of 50 PRO instruments were identified. The 4 most frequently used PROs were the Dizziness Handicap Inventory, Activities-specific Balance Confidence scale, Vertigo Symptom Scale-short form, and visual analog scale. Of these 4 PROs, 3 were validated for use in patients with vestibular disease and 1 was validated in community-dwelling older individuals with balance impairments. Items across the 4 PROs were categorized into 3 domains based on the International Classification of Functioning, Disability and Health: activity, participation, and body functions and structures.

Conclusions: None of the most commonly used PRO instruments were validated for use in community-dwelling older adults with age-related vestibular loss. Nevertheless, the 3 common domains of items identified across these 4 PRO instruments may be generalizable to older adults and provide a basis for developing a PRO instrument designed to evaluate the effectiveness of interventions targeted toward age-related vestibular loss.