Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Adverse effects
Systematic review	54 people; mean baseline AHI: 50 in CPAP alone group v 42 in CPAP plus humidification group Data from 1 RCT	nasal symptoms with CPAP plus humidification with CPAP Absolute results not reported	P <0.05 See further information on studies for methodological weaknesses	Effect size not calculated	CPAP plus humidification