Ricci 1987.

Study characteristics
Methods	Double‐blind, parallel trial 30 to 40‐week duration
Participants	10 patients with Ménière's disease (grade III)
Interventions	Betahistine 8 mg 3 times daily versus placebo
Outcomes	Vertigo (grade I). Reduced with betahistine Hearing loss (grade I). No difference from placebo Tinnitus (grade I). No difference from placebo Aural fullness (grade I). No difference from placebo
Notes	Allocation bias: medium Attrition bias: medium
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear