Mira 2003.

Study characteristics
Methods	Randomised, double‐blind, parallel trial
Participants	144 patients (81 Ménière's disease, 63 BPPV) 41 Ménière's patients allocated to betahistine group, 40 to placebo
Interventions	Betahistine dihydrochloride 16 mg twice daily versus placebo (identical in colour, weight and flavour)
Outcomes	Vertigo (grade I). Reduced with betahistine Quality of life (grade III). Improved activity levels at 2 and 3 months with betahistine
Notes	Allocation bias: low Attrition bias: medium
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	A ‐ Adequate