Horak 1992.

Methods	Design: randomised controlled trial
Participants	Number: 25 Age: not reported Gender: not reported Setting: not reported Eligibility criteria: peripheral vestibular dysfunction diagnosed by neuro‐otologist for BPPV, inner ear concussion syndrome, reduced unilateral vestibular function, 18 to 60 years of age Exclusion criteria: CNS involvement, spontaneous fluctuating vestibular symptoms, significant orthopaedic or cardiac problems, or non‐compliance with the treatment programme Baseline characteristics: no differences reported
Interventions	Intervention group: VR (n = 14) Comparator group 1: general conditioning exercises (n = 4) Comparator group 2: medication (meclizine or Valium) (n = 8) VR versus control (sham) versus other non‐VR (medication)
Outcomes	Primary outcome: DI Secondary outcomes: posturography, SOOL, questionnaire, positional vertigo ‐ number of positions, DI and duration
Notes	Number of participants available for post intervention assessments not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information about the sequence generation process
Allocation concealment (selection bias)	Unclear risk	Insufficient information about the method of allocation
Blinding (performance bias and detection bias) All outcomes	Low risk	Participants, physicians and outcome assessors were all blinded to group allocation
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants were available for follow‐up assessments
Selective reporting (reporting bias)	Unclear risk	Some outcome data not reported for meta‐analysis
Other bias	Low risk	The study appears to be free of other sources of bias