Yardley 1998.

Methods	Design: randomised controlled trial
Participants	Number: 143 Age: intervention group: mean age 60.1 (SD 15.2), comparator group: mean age 59.6 (SD 15.9) Gender: intervention group: 15 males, comparator group: 13 males Setting: conducted in 10 general practices, delivered by primary care nurse Eligibility criteria: dizziness of vestibular origin. Mixed aetiology ‐ diagnosed where possible by medical records (1/3). Possibility of central pathology Exclusion criteria: vigorous head or body movement contraindicated, non‐vestibular cause for dizziness, multiple, life‐threatening or progressive CNS disorders Baseline characteristics: nil reported
Interventions	Intervention group: VR (education, head and body movements, relaxation, breathing, encouragement to function) (n = 67) Comparator group: control (n = 76) VR versus control (usual medical care)
Outcomes	Primary outcome: VSS Secondary outcomes: VHQ, HADS, sharpened Romberg, provocative movements
Notes	16 participants dropped out of the study before follow‐up and were excluded from the analysis; those who dropped out were more likely to report a higher number of movements that provoked their dizziness
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number tables were used in 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	High risk	Neither the therapists, outcome assessors nor participants were blinded to group allocation
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data were missing for various measures across many time points but this is adequately explained
Selective reporting (reporting bias)	Low risk	Study protocol not available but all data appear to be reported
Other bias	Low risk	The study appears to be free of other sources of bias