Guneri 2012.

Study characteristics
Methods	Allocation: randomised, but no further information Design: parallel‐group
Participants	Number: 50 analysed Age: 18 to 79 Gender: 62.5% F, 37.5% M Setting: university hospital? Eligibility criteria: benign paroxysmal positional vertigo with positive Dix‐Hallpike testExclusion criteria: vestibulo‐suppressant and ototoxic medications, central nervous system disorders and history of previous ear surgery Baseline characteristics: not stated
Interventions	Epley particle repositioning manoeuvre plus betahistine 24 mg twice a day versus Epley particle repositioning manoeuvre plus placebo over 2 weeks Intervention group: n = 24 Comparator group: n = 26 Use of additional interventions: Epley repositioning manoeuvre used in both groups equally
Outcomes	Primary outcome: Dix‐Hallpike positioning tests Secondary outcomes: Dizziness Handicap Inventory, Vertigo Symptom Scale, Vestibular Activities of Daily Living Scale, European Evaluation of Vertigo
Funding sources	Appropriate disclosures made
Declarations of interest	Appropriate disclosures made
Notes	Group 1 (Epley manoeuvre only) was discounted for this review as not relevant to review scope. Potential for bias due to additional intervention is noted
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	Low risk	"Physician doing Epley manoeuvre did not know who would be allocated." "... second physician who supplied medication was also unaware".
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	"Double blind", but no further information
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Attrition not mentioned Participants lost to follow‐up: not reported
Selective reporting (reporting bias)	High risk	Adverse events not reported
Other bias	Unclear risk	—