Table.

GRADE Evaluation of interventions for Menière's disease.

Important outcomes	Frequency and severity of acute attacks of vertigo, Functional impairment, Hearing acuity, Quality of life, Sensation of aural fullness, Severity of tinnitus
Studies (Participants)	Outcome	Comparison	Type of evidence	Quality	Consistency	Directness	Effect size	GRADE	Comment
What are the effects of intratympanic interventions to prevent attacks and delay disease progression of Menière’s disease?
2 (50)	Frequency and severity of acute attacks of vertigo	Intratympanic gentamicin versus placebo/sham treatment/no treatment/usual care	4	–3	0	–1	0	Very low	Quality points deducted for weak methods, incomplete reporting of results, and sparse data; directness point deducted for clinical heterogeneity between RCTs
2 (50)	Hearing acuity	Intratympanic gentamicin versus placebo/sham treatment/no treatment/usual care	4	–3	0	–1	0	Very low	Quality points deducted for weak methods, incomplete reporting of results, and sparse data; directness point deducted for clinical heterogeneity between RCTs
1 (28)	Severity of tinnitus	Intratympanic gentamicin versus placebo/sham treatment/no treatment/usual care	4	–2	0	–1	0	Very low	Quality points deducted for weak methods and sparse data; directness point deducted for unclear statistical analysis between groups
1 (28)	Sensation of aural fullness	Intratympanic gentamicin versus placebo/sham treatment/no treatment/usual care	4	–3	0	0	0	Very low	Quality points deducted for weak methods, incomplete reporting of results, and sparse data
1 (18)	Frequency and severity of acute attacks of vertigo	Intratympanic corticosteroids versus placebo/sham treatment/no treatment/usual care	4	–3	0	0	0	Very low	Quality points deducted for weak methods, incomplete reporting of results, and sparse data
2 (38)	Hearing acuity	Intratympanic corticosteroids versus placebo/sham treatment/no treatment/usual care	4	–3	0	0	0	Very low	Quality points deducted for weak methods, incomplete reporting of results, and sparse data
2 (38)	Severity of tinnitus	Intratympanic corticosteroids versus placebo/sham treatment/no treatment/usual care	4	–3	0	0	0	Very low	Quality points deducted for weak methods, incomplete reporting of results, and sparse data
1 (18)	Functional impairment	Intratympanic corticosteroids versus placebo/sham treatment/no treatment/usual care	4	–2	0	0	0	Low	Quality points deducted for weak methods and sparse data

We initially allocate 4 points to evidence from RCTs, and 2 points to evidence from observational studies. To attain the final GRADE score for a given comparison, points are deducted or added from this initial score based on preset criteria relating to the categories of quality, directness, consistency, and effect size. Quality: based on issues affecting methodological rigour (e.g., incomplete reporting of results, quasi-randomisation, sparse data [<200 people in the analysis]). Consistency: based on similarity of results across studies. Directness: based on generalisability of population or outcomes. Effect size: based on magnitude of effect as measured by statistics such as relative risk, odds ratio, or hazard ratio.