Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Hearing
Systematic review	Children with otitis media with effusion (OME; number of children not reported) 3 RCTs in this analysis	Hearing 6 months with ventilation tube plus adenoidectomy with no treatment Absolute results not reported	Mean difference ranged from about 8 dB to about 20 dB Reported as significant 95% CI presented graphically	Effect size not calculated	Ventilation tube plus adenoidectomy
Systematic review	Children with OME (number of children not reported) 3 RCTs in this analysis	Hearing 12 months with ventilation tube plus adenoidectomy with no treatment Absolute results not reported	Mean difference ranged from about 2 dB to about 10 dB Reported that only one of the three RCTs found a significant benefit with ventilation tube plus adenoidectomy Mean differences and 95% CIs for each RCT displayed graphically