Burkin 1967.

Study characteristics
Methods	Allocation: randomised, but no further details given Design: cross‐over with data extractable before cross‐over occurred
Participants	Number: 22 analysed Age: 37 to 58 Gender: 50% female Setting: ENT department Eligibility criteria: investigator's clinical diagnosis of Ménière's disease Exclusion criteria: not specified Baseline characteristics: not given
Interventions	Betahistine 4 mg 4 times a day versus placebo over 2 weeks before cross‐over Intervention group: n = 11 Comparator group: n = 11 Use of additional interventions: none
Outcomes	Primary outcome: dizziness ‐ present or absent dichotomy Secondary outcomes: adverse events
Funding sources	Not specified
Declarations of interest	Not given
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomised"; no further information
Allocation concealment (selection bias)	Unclear risk	Method not stated
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Double‐blind; "neither patient nor investigator knew which group" but no further details
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Double‐blind
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No information Participants lost to follow‐up: not specified
Selective reporting (reporting bias)	Low risk	Appropriate outcomes
Other bias	Unclear risk	—