Diegel‐Vacek 2016.

Methods	Non‐randomised trial in 1 centre in the USA Study period: 3 observation days in a 3‐week period: day 1, day 14, day 21. Dates not stated.
Participants	All healthcare workers
Interventions	Visual light as reminder
Outcomes	Observed hand hygiene compliance
Notes	Funding source: None Declaration of interest: None
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Non‐random allocation
Allocation concealment (selection bias)	Low risk	Room assigned to be intervention or control room prior to start of study
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants were aware of observer and purpose of the light
Blinding of outcome assessment (detection bias) All outcomes	High risk	Blinding was not possible
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	Low risk	No evidence
Baseline outcomes	Unclear risk	No baseline hand hygiene compliance assessed
Baseline characteristics	High risk	No report of characteristics of patients, staff or room set‐up
Protection from contamination	High risk	The same staff entered both rooms and were aware of the light cue in the intervention room