Villafane 1996.

Methods	Randomized parallel study comparing 2 types of HME to HH.
Participants	Inclusion criteria: people in ICU requiring mechanical ventilation. Mean age: HME 63 years, HH 60 years. Exclusion criteria: haemorrhagic disorders, intubated for > 24 hr before admission. Respiratory diagnosis: not stated. Mean SAPS score: HME 17, HH 17. Setting: ICU, France.
Interventions	HME (hydrophobic): BB2215 (Pall). n = 8. HME: Hygrobac (DAR) changed daily. n = 8. HH: MR310 (Fisher & Paykel) set at 32 ºC. n = 7. Time in study (mean): HME 6 days, HH 6 days.
Outcomes	Artificial airway occlusion.
Notes	Funding: not stated.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not stated.
Allocation concealment (selection bias)	Unclear risk	Not stated.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not stated.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Number enrolled not stated.
Selective reporting (reporting bias)	High risk	No protocol available and only 1 primary outcome reported.
Other bias	Low risk	None identified.