Fogas 2013.

Methods	Parallel‐group randomised controlled trial
Participants	Baseline characteristics Number randomised: 94 participants Number analysed: 79 participants Proton pump inhibitors Age (years; mean (range)): 67 (56‐77) Number of participants at baseline (n): 38 Gender (male/female; n): 23/15 H2 receptor antagonists Age (years; mean (range)): 72 (58‐79) Number of participants at baseline (n): 41 Gender (male/female; n): 25/16 Inclusion criteria Mechanically ventilated for longer than 48 hours Exclusion criteria Admission diagnosis of pneumonia or other acute inflammatory pulmonary disease Severe sepsis/septic shock Regular use of proton pump inhibitors or H2 receptor antagonists Baseline imbalances: no significant difference (P > 0.05) between groups regarding demographics
Interventions	Proton pump inhibitors Dose (total/d): ‐ Duration of treatment (days): ‐ Route: ‐ Concomitant medications: ‐ Intervention: ‐ H2 receptor antagonists Dose (total/d): ‐ Duration of treatment (days): ‐ Route: ‐ Concomitant medications: ‐ Intervention: ‐ Adherence to treatment: ‐ Duration of follow‐up: ‐ Duration of trial: ‐
Outcomes	Outcomes reported in trial and used in review Clinically important upper GI bleeding VAP diagnosed by leucocytosis, increased PCT level, fever, purulent tracheal secretion, positive microbiological result of tracheal sample, and new/increased infiltrate on chest X‐ray Outcomes sought but not reported in trial Mortality Duration of ICU stay Duration of intubation Blood transfusion Adverse events of interventions Outcomes reported in trial but not used in review Nil
Notes	Setting: General ICU, University of Szeged, Hungary Sponsorship source: ‐ Conflicts of interest: ‐ Comments: conference abstract Ethics approval: Quote: "After ethics committee approval ..." Informed consent: ‐ Clinical trials registration: ‐ Sample size calculation: Quote: "However, the completion of the study on the planned 198 patients is required to come to the final conclusions"
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: no details reported
Allocation concealment (selection bias)	Unclear risk	Comment: no details reported
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Comment: no details reported, but lack of blinding unlikely to introduce bias to the outcome and outcome measures
Blinding (detection bias) Clinically important upper GI bleeding	High risk	Comment: no details reported, and no diagnostic criteria described
Blinding (detection bias) Nosocomial pneumonia	Low risk	Comment: Pneumonia was an objective outcome that was diagnosed as per the definition in the study protocol
Blinding of outcome assessment (detection bias) Adverse reactions of interventions	Unclear risk	Comment: no details reported
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: no incomplete reporting of outcome data. Patient flow was reported transparently; attrition was unlikely to have introduced bias to the results
Selective reporting (reporting bias)	Low risk	Comment: All outcomes listed are reported in the Results section. Conference abstract
Other bias	Unclear risk	Comment: no other sources of bias suspected, but not enough details reported in conference abstract