Ho 2004.

Study characteristics
Methods	Non‐blinded, parallel‐group randomised controlled trial with 15 days duration of treatment and 1.5‐month duration of follow‐up
Participants	Setting: tertiary referral centre, Taiwan, January 2001 to June 2003 Sample size: Number randomised: 29 Number completed: 29 Primary/secondary therapy: secondary therapy after failure of primary therapy Primary therapy: methylprednisolone oral 1 mg/kg per day for 5 days, followed by tapering to 10 mg/day for another 5 days plus vasodilators (nicametate citrate, 3x per day), vitamin B‐complex and fludiazepam (0.25 mg 3x per day) and carbogen inhalation therapy (95% O2 and 5% CO2) Participant (baseline) characteristics: age/sex (male, female)/baseline hearing loss at start of therapy/start of initial treatment/start of treatment: Group I (intratympanic): 46.1 ± 19.9 y/7 m, 8 f/81.04 ± 13.23 dB HL/9.7 ± 12.0 d/not reported Group II (no treatment): 51.4 ± 14.4 y/9 m, 5 f/91.78 ± 10.40 dB HL/4.4 ± 3.5 d/not reported Inclusion criteria: 1) unilateral severe or profound idiopathic sudden SSNHL, 2) HL occurring within 24 hours, 3) no otologic history in the affected ear, and 4) hearing improvement < 30 dB in PTA, no recovery of hearing, or worsening of hearing after primary therapy Exclusion criteria: mumps, measles, rubella, cytomegaly viruses and retrocochlear lesion
Interventions	General comparison: intratympanic corticosteroid therapy versus no treatment Intervention group (n = 15*): "intratympanic therapy": intratympanic injection of dexamethasone, 4 mg/mL, 0.4 to 0.7 mL, 3 injections total, 1x per week Comparator group (n = 14*): "no therapy": continuation of initial oral "standard therapy" without corticosteroids: vasodilators (nicametate citrate, 3 times a day orally), vitamin B‐complex and benzodiazepine (fludiazepam, 0.25 mg 3 times a day orally) Use of additional interventions (common to both treatment arms): none *intention‐to‐treat analysis
Outcomes	Primary outcome measure: Proportion of patients whose hearing is improved (criterion of improvement final PTA < 25 dB HL or PTA decrease > 30 dB in PTA/Furuhashi criteria) Secondary outcomes: Change in hearing threshold with pure tone average Adverse events Primary endpoint for hearing threshold evaluation: 49 days Used PTA: 6PTA (0.25, 0.5, 1, 2, 4, 8 kHz)
Funding sources	No information available
Declarations of interest	No information provided
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Patients … were further randomly assigned". Method of random sequence generation is not described.
Allocation concealment (selection bias)	Unclear risk	Method of concealment is not described.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Open‐label trial, no blinding.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information to permit judgement (not mentioned).
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing outcome data reported.
Selective reporting (reporting bias)	High risk	Not all pre‐specified follow‐up time points were reported.
Other bias	High risk	No sample size calculation performed. Mean of hearing threshold before treatment in control group not reported. Treatment delay from onset to secondary treatment in patients not reported but reported treatment delay to initial treatment and duration of initial treatment. Possible difference in treatment delay from onset between groups.