| Methods |
Randomised, double‐blinded |
| Participants |
Setting: general community patients suffering from unilateral ISSHL who were referred to Chaim Sheba Medical Center
Country: Israel
Total number: 41
Mean age: 36
Male to female ratio: 19/22
Tinnitus (no. of patients): 23
Vertigo (no. patients): 13
Duration of treatment: 5 days |
| Interventions |
Group 1: prednisone tablet 1 mg/kg once a day
Group 2: placebo tablets (similar to prednisolone tablets)
Group 3: carbogen (5% CO2 + 95% oxygen) inhalation for 30 minutes, 6 times per day
Group 4: room air inhalation for 30 minutes, 6 times per day |
| Outcomes |
Outcome measures: objective audiometry performed on admission, on day 6 and at follow‐up (range 14 to 90 days, average 33 days). The authors evaluated and compared the average hearing level at 6 frequencies (250 to 8000 Hz), the pure‐tone average of speech frequencies (500, 1000, 2000 Hz) and the high‐tone average (4000, 8000 Hz). An "improvement" was considered to be a minimum 15 dB change between the average hearing level evaluated at the different times mentioned. |
| Notes |
Quality score: C |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
High risk |
The randomisation was made on a rotation basis. This method of randomisation did not provide adequate concealment as the investigators would know which patient entered which group. |
| Allocation concealment (selection bias) |
High risk |
Inadequate. Based on sequential allocation of the participants to each treatment group. The investigators would know which patient entered which group. |
| Blinding (performance bias and detection bias)
All outcomes |
Low risk |
Both the steroid and placebo tablets looked the same and were marked as "Prednisone A" or "Prednisone B". Only the pharmacist and the study controller (who did not participate in the decision making) knew the real composition of the medications. |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
There was no loss to follow‐up or drop‐out from the study and intention‐to‐treat analysis was performed by the authors |
| Selective reporting (reporting bias) |
Low risk |
There was no evidence of selective reporting |
| Other bias |
Low risk |
|
