Melchior 1996.

Study characteristics
Methods	RCT, the Netherlands
Participants	161 psychiatric nurses in long‐stay settings
Interventions	1) Experimental: support and advice given by nurse managers or quality care co‐ordinators: Participants were assigned to patients as primary nurses and given advice by nurse managers or quality care co‐ordinators and they followed a training programme about communication skills over a year. 2) Control: no intervention
Outcomes	MBI
Identification
Notes	MBI‐EE included in analysis 3.3.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Random sampling was used to select 492 nurses to complete the questionnaires." (p. 696)
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants not blinded.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Participants were not blinded whereas outcomes are self‐reported.
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: "Two main problems were encountered in this study, namely a high drop‐out rate largely due to job turnover among nurses, and the imitation of the intervention by the control group." (p. 697)  A total of 51.6% of the participants dropped out during the study
Selective reporting (reporting bias)	Low risk	All outcomes reported.
Other bias	Low risk	We did not find any indications of other sources of bias.