Li 2011.

Study characteristics
Methods	Non‐blinded, parallel‐group randomised controlled trial with 15 days duration of treatment and 2‐month duration of follow‐up
Participants	Setting: tertiary referral centre, China, July 2006 to September 2009 Sample size: Number randomised: 65 Number completed: 65 Primary/secondary therapy: secondary therapy after failure of primary therapy Primary therapy: 1 mg/kg prednisolone each day for 5 days followed by a division into 4 doses with a gradual tapering over the course of 9 days Participant (baseline) characteristics: age/sex (male, female)/baseline hearing loss at start of therapy/start of initial treatment/start of treatment: Group I (intratympanic): 53.5 (18 to 72) y/9 m, 15 f/60.7 ± 58.79 dB HL/not reported/not reported Group II (ear canal): 50.0 (21 to 69) y/10 m, 11 f/61.9 ± 50.87 dB HL/not reported/not reported Group III (no treatment): 51.0 (22 to 73) y/7 m, 13 f/60.8 ± 49.19 dB HL/not reported/not reported Inclusion criteria: 1) SSNHL, which was defined as a sensorineural hearing loss of at least 30 dB at 3 contiguous frequencies over a period of ≤ 3 days; 2) time from the onset of hearing loss to the treatment was ≤ 14 days; 3) no history of ear diseases; 4) no specific causes for the SSNHL after proper investigation; 5) primary therapy (see above); 6) average of PTA was < 30 dB for the affected ear or < 10 dB from the contralateral ear at the end of primary treatment Exclusion criteria: 1) bilateral hearing loss; 2) other contraindications to the administration of intratympanic (IT) steroids; 3) the presence of a neoplasm or recent chemotherapy or radiation therapy; 4) congenital cochlear malformations or the presence of otitis media with an abnormal tympanogram; 5) recent use of ototoxic medications; 6) liver or renal dysfunction, and/or 7) pregnancy
Interventions	General comparison: intratympanic corticosteroids versus ear drops or versus no therapy Intervention group (n = 24*): "intratympanic therapy": intratympanic injection of methylprednisolone, 40 mg/mL, 1 mL, 4 injections total, 2 x every 3 days within 15 days Comparator group I (n = 21*): "ear canal drops": methylprednisolone, 40 mg/mL, 1 mL as drops in ear canal onto intact tympanic membrane, 4 applications total, 1x every 3 days within 15 days Comparator group II (n = 20*): "no treatment": none Use of additional interventions (common to all treatment arms): none *intention‐to‐treat 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 decease in PTA) Adverse events Primary endpoint for hearing threshold evaluation: 60 days Used PTA: 4PTA (0.5, 1, 2, 4 kHz)
Funding sources	Ministry of Education New Faculty Foundation (20090171120082) and Guangdong Province Medical Science Foundation (B2009075)
Declarations of interest	No information provided
Notes	The treatment arm patients treated by corticosteroid ear canal drops were not included in the meta‐analysis because they cannot be assigned to either the intratympanic or systemic treatment condition in our opinion
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "[patients] were randomly divided into the IT treatment group (n = 24), the ear drop group (n = 21), and the control group (n = 20)." 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)	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 from onset to secondary treatment in patients not reported. Unexplained difference in numbers of patients among groups.