Mertz 2010.

Methods	Design: Cluster‐randomised trial Study period: 3 month baseline assessment (October ‐ December 2006) then trial was conducted for 1 year (June 2007 ‐ May 2008) with assessments conducted weekly (5 randomly‐selected 15‐minute periods per week per unit) Canada
Participants	All healthcare workers on 30 adult hospital wards in 3 acute care hospitals
Interventions	Performance feedback (pooled not individual), small‐group teaching seminars, posters and pamphlets, unit‐generated target adherence level and approaches to increase awareness of hand hygiene Control: ABHR dispensers installed
Outcomes	Adherence to hand hygiene: considered successful if hand hygiene occurred when it was deemed necessary (using WHO indications for hand hygiene) and if duration of hand hygiene met pre‐set criteria. Incidence of hospital‐acquired MRSA colonisation (cases per 1000 patient‐days)
Notes	Appropriate analysis: unit of analysis for hand hygiene was at the level of the clusters Funding source: Physicians’ Services Incorporated Foundation of Ontario, Canada and Swiss National Science Foundation Grant Declaration of interest: None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Allocated to arm using random numbers table; statistician was not part of study team
Allocation concealment (selection bias)	Low risk	Allocation was by unit and performed at start of study
Blinding of participants and personnel (performance bias) All outcomes	High risk	Included posters and performance feedback so participants aware of the intervention
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Unclear if outcomes were assessed blindly
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing data (missed opportunities) unlikely to be very different in different arms
Selective reporting (reporting bias)	Low risk	No evidence of selective reporting
Other bias	High risk	ABHR dispensers installed hospital wide during study; 1 MRSA outbreak
Baseline outcomes	Low risk	Similar hand hygiene compliance at baseline
Baseline characteristics	High risk	Only reported that sinks and ABHR availability were similar; no comparison of patients, staffing, etc
Protection from contamination	High risk	Authors suggested contamination of control group likely; control units were in same hospitals as intervention groups