Hoberman 1997.

Methods	Randomisation claimed, but method not described Baseline comparability documented. Investigators were unaware of treatment assignment ITT analysis
Participants	USA 54 children in primary care or emergency department aged 5 to 19 years with ear pain and eardrum findings indicative of AOM
Interventions	Treatment: anaesthetic ear drops (antipyrine, benzocaine, glycerine) Control: olive oil drops Duration: 30 minutes All children were also given acetaminophen (15 mg/kg in a single dose)
Outcomes	Ear pain was assessed by means of 2 visual analogue scales at baseline, 10, 20, 30 minutes after instillation, and an average ear pain score was determined Four measures were used: 1) proportion of subjects who showed 50% reduction; 2) proportion of subjects who showed 25% reduction; 3) proportion of subjects who showed a 1 or more point reduction; 4) mean score over time
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Children were "randomly assigned". No further information provided
Allocation concealment (selection bias)	Unclear risk	No mention of sequentially numbered, opaque, sealed envelopes or of central randomisation by a third party
Blinding (performance bias and detection bias) All outcomes	Low risk	"Investigators were unaware of the study drug assignment"
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	"One patient in the Auralgan group did not receive a T20 evaluation". However the difference between the 2 groups was not statistically significant at this time point and even if treatment failure was assumed the missing value is not likely to have a significant impact