Austin 1993.

Methods	Double‐blind, randomised, controlled study
Participants	107 people were initially randomised; 76 completed follow‐up until acute recovery and were included in the study analyses Participants were treated within 5 days of onset Sex: male 39 (51%), female 37 (49%) Age: mean 36.8 years, range 18 to 70 years 37 cases (49%) right side palsy and 39 cases (51%) left side palsy
Interventions	Prednisone (n = 35): in a scheduled dosage (30 mg twice daily for 5 days reducing to 20 mg twice daily on day 6, 15 mg twice daily on day 7, 10 mg twice daily on day 8, 5 mg twice daily on day 9, and 5 mg once daily on day 10) Equivalent placebo (n = 31)
Outcomes	Primary outcome: time to resolution in days of facial function as defined by the House‐Brackmann scale Secondary outcomes: distribution of facial nerve grade at 6 months after recovery, in addition to crocodile tears and anxiety during follow‐up Follow‐up up to 9 months
Funding	Not stated
Conflicts of interest	Not stated
Date conducted	1 October 1989 to 31 December 1990
Notes	Good recovery defined as grade I or II of the House‐Brackmann scale
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Stated to be randomised at the pharmacy but details not given
Allocation concealment (selection bias)	Unclear risk	Allocation of participants not described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "The study was blinded to both the patient and the clinical investigators". Further details of blinding not given
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "The study was blinded to both the patient and the clinical investigators". Further details of blinding not given
Incomplete outcome data (attrition bias) All outcomes	High risk	107 participants randomised, 31 did not attend for follow‐up assessment. 76 allocated to prednisone or placebo Analysis 6 months after resolution of Bell's palsy included 53 participants (23 prednisolone and 30 placebo), representing over 50% loss to follow‐up at this point. Reasons for additional drop‐outs at 6 months not described
Selective reporting (reporting bias)	Low risk	All primary outcomes reported
Other bias	Low risk	Single‐centre study