Grap 2011.

Study characteristics
Methods	Study design: RCT Location: Virginia, USA Number of centres: 2 units in same hospital, level 1 trauma centre Study period: not stated Funding source: Triservice Nursing research programme grant TSNRP MDA‐905‐03‐TS02
Participants	Setting: surgical trauma ICU & neuroscience ICU Inclusion criteria: patients intubated within 12 hours of admission to trauma centre (intubation may have occurred in emergency department, in the field or in pre‐hospital setting) Exclusion criteria: previous endotracheal tube placed in 48 hours prior to admission, clinical diagnosis of pneumonia on admission, burn injuries, edentulous persons Number randomised: 152, 7 lost, enrolled sample 145 (71/74) (only 75 were still intubated after 48 hours) Number evaluated: at 48 or 72 hours = 60 (36/24) (for VAP) 39 (21/18) Baseline characteristics: not reported for each randomised group Those with 48/72 hour data: ‐ Experimental group: n = 36, M/F 27/9, APACHE II 70.69 ± 30.14 ‐ Control group: n = 24, M/F 11/13, APACHE II 60.46 ± 23.45
Interventions	Comparison: chlorhexidine applied by swab versus usual care Experimental group: 1 x 5 mL dose of chlorhexidine 0.12% applied to all areas of the oral cavity by swab within 12 hours after intubation. All participants received the usual oral comfort care (details not reported). Control group: usual oral comfort care
Outcomes	1. Incidence of VAP 2. CPIS score 3. APACHE III 4. TRISS 5. Oral health (DMFT)
Notes	Sample size calculation: not reported (but pilot study published in 2004) Email sent and reply received to clarify the data
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"The subjects were randomised to a treatment group or control group using a block randomisation scheme".
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not possible because no placebo used
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not mentioned
Incomplete outcome data (attrition bias) All outcomes	High risk	Huge attrition, and reasons for losses not described for each group. Conclusions based on 39/152 (26%) of those originally randomised to treatment or control
Selective reporting (reporting bias)	High risk	Primary outcome planned was development of VAP but inclusion criteria used in this study meant that fewer than half those randomised were at risk of developing VAP.
Other bias	High risk	Study report noted statistically significant difference in gender and CPIS score between groups at baseline. No baseline characteristics data reported for each randomised group, and likely that important prognostic factors e.g. place of intubation, surgery, may have been different in each group