Peng 2008.

Study characteristics
Methods	Non‐blinded, parallel‐group randomised controlled trial with 10 or 20 days duration of treatment and a 17 or 27 days duration of follow‐up
Participants	Setting: tertiary referral centre, China, 2005 to 2007 Sample size: Number randomised: 84 Number completed: 84 Primary/secondary therapy: primary therapy Participant (baseline) characteristics: age/sex (male, female)/baseline hearing loss at start of therapy/start of treatment: Group I (intratympanic): 43.8 ± 13.4 y/not provided/72.0 ± 18.6 dB HL/6.2 ± 2.4 d Group II (pharyngotympanic tube): 42.5 ± 11.6 y/not provided/71.0 ± 18.7 dB HL/5.8 ± 3.5 d Group III (systemic intravenous): 45.2 ± 11.5 y/not provided/70.0 ± 17.6 dB HL/5.2 ± 3.1 d Group IV (systemic oral): 42.1 ± 10.2 y/not provided/69.0 ± 16.5 dB HL/5.2 ± 2.8 d Inclusion criteria: unilateral ISSNHL Exclusion criteria: middle ear or retrocochlear disease, previous history of hearing loss, previously treatment, age over 65 years
Interventions	General comparison: intratympanic corticosteroids versus injection of corticosteroids through pharyngotympanic tube versus systemic corticosteroids by intravenous and oral administration Intervention group I (n = 21*): "intratympanic therapy": intratympanic injections of dexamethasone 5 mg, 10 injections in total, 1x every day for 10 days Intervention group II (n = 21*): "injection through pharyngotympanic tube": injections of dexamethasone 5 mg with pharyngotympanic tube catheter, 10 injections in total, 1x every day for 10 days Comparator group I (n = 21*): "systemic therapy i.v.": dexamethasone intravenous 10 mg per day for 4 days; after 4 days 5 mg per day for 6 days Comparator group II (n = 21*): "systemic therapy p.o.": dexamethasone oral 0.75 mg, 3 times per day; after 7 days, 0.75 mg, 2 times per day for 3 days Use of additional interventions (common to all treatment arms): intravenous low molecular dextran 500 mL, buflomedil 0.2 g, energy mixture. Intramuscular injection of vitamin B1 0.1 g, B12 0.5 mg, once a day for 10 days Patients underwent 1 or 2 treatment cycles depending on pure tone audiometry after the first treatment cycle. *intention‐to‐treat analysis
Outcomes	Primary outcome measure: Proportion of patients whose hearing is improved (criterion of improvement > 15 dB decease in PTA) Secondary outcomes: Change in hearing threshold with pure tone audiometry Primary endpoint for hearing threshold evaluation: 17 or 27 days Used PTA: 4PTA (0.5, 1, 2, 4 kHz)
Funding sources	No information available
Declarations of interest	No information provided
Notes	Data from the oral systemic treatment arm were included in the review
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Randomisation according to date of visit of patients.
Allocation concealment (selection bias)	High risk	No allocation concealment possible because of the method of random sequence generation used.
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. Wide range of treatment delay from onset among included patients. Different time of treatment (10 or 20 days) and follow‐up (17 or 27 days) between patients within groups.