Lorente 2006.

Methods	Randomized parallel study comparing HME to HH.
Participants	Inclusion criteria: adults expected to require ventilation for ≥ 5 days. Mean age: HME 56 years, HH 55 years. Exclusion criteria: aged < 18 years, HIV, blood leukocytes < 1000/mm3, solid or haematological tumour, immunosuppressive therapy. Respiratory diagnosis: HME 24%, HH 31%. Mean APACHE II score: HME 18.11, HH 18.72. Setting: ICU, Spain.
Interventions	HME: Edith Flex (Datex‐Ohmeda) changed at 48‐hr intervals. n = 53. HH (heated wire): MR 850 (Fisher & Paykel) and Aerodyne 2000 (Tyco Healthcare/Nellcor) set at 37 ºC. n = 51. Time in study (mean): HME 20 days, HH 21 days.
Outcomes	VAP.
Notes	Funding: not stated.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Patients were assigned ‐‐‐ by a random number list generated using Excel software."
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	High risk	Data from participants available at follow‐up.
Selective reporting (reporting bias)	High risk	No protocol available and only 1 primary outcome reported.
Other bias	Low risk	None identified.