Wu 2011.

Study characteristics
Methods	Triple‐blinded, parallel‐group, randomised controlled trial with 14 days duration of treatment and 1‐month duration of follow‐up
Participants	Setting: multicentre trial, China, October 2007 to September 2008 Sample size: Number randomised: 60 Number completed: 55 Primary/secondary therapy: secondary therapy after failure of primary therapy Primary therapy: 5 days of an intravenous steroid therapy with Solu‐Medrol 40 mg every 12 h, plus 5 days of tapering with oral prednisolone starting from a daily divided dose of 1 mg/kg Participant (baseline) characteristics: age/sex (male, female)/baseline hearing loss at start of therapy/start of initial treatment/start of treatment: Group I (intratympanic): 49.1 ± 14.2 y/9 m, 18 f/64.6 ± 17.7 dB HL/4.4 ± 1.6 d/not reported Group II (placebo): 47.4 ± 15.7 y/9 m, 19 f/69.9 ± 18.5 dB HL/4.7 ± 1.9 d/not reported Inclusion criteria: 1) sudden unilateral sensorineural hearing loss (occurring within 72 h) of greater than 30 dB in at least 3 contiguous frequencies, 2) normal or nearly normal hearing in the better ear (4‐frequency pure tone average (PTA) < 30 dB), 3) currently receiving systemic steroid therapy that started within 7 days of SSHL onset, 4) a post‐systemic therapy PTA difference between impaired and healthy ears of greater than 20 dB, 5) a type A tympanogram and 6) older than 18 years Exclusion criteria: 1) the presence of a neoplasm or retrocochlear lesion, 2) the presence of congenital cochlear malformations, 3) the presence of otitis media, 4) the presence of other neurologic disorders, 5) recent use of ototoxic medications, 6) liver or renal dysfunction and 7) pregnancy
Interventions	General comparison: intratympanic corticosteroids versus placebo Intervention group (n = 27*): "intratympanic therapy": intratympanic injection of dexamethasone, 4 mg/mL, 0.5 mL, 4 injections total, 1x every 4 days Comparator group (n = 28*): "placebo": intratympanic injection of normal saline, 0.5 mL, 4 injections total, 1x every 4 days Use of additional interventions (common to both treatment arms): none *per protocol analysis
Outcomes	Primary outcome measure: Change in hearing threshold with pure tone audiometry Secondary outcomes: Proportion of patients whose hearing is improved (criterion of improvement > 10 dB decrease in PTA) Adverse events Primary endpoint for hearing threshold evaluation: 30 days Used PTA: 4PTA (0.5, 1, 2, 4 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)	Low risk	Quote: "independent physician used a computer‐generated randomisation schedule".
Allocation concealment (selection bias)	Low risk	Quote: "computer‐generated randomisation list was given to the pharmacy departments".
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "The principal physician was blind to the drugs, …. The subjects were blinded to the drugs."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "…and the audiologists were blind to the subjects".
Incomplete outcome data (attrition bias) All outcomes	High risk	Reported moderate missing outcome data (5% to 10%) was related to the advised treatment arm (8.3%).
Selective reporting (reporting bias)	Low risk	No indication of selective reporting in the outcome parameters addressed by the review.
Other bias	High risk	No sample size calculation performed. Treatment delay to secondary therapy in patients not reported.