Background Recent literature reviews lament the paucity of high-quality intervention studies designed to test safety culture improvement in hospitals. The current study adapts an empirically supported strategy developed for manufacturing companies by focusing on patient care and safety messages head nurses communicate during daily conversations with nurses.

Methods The study was designed as randomised control trial coupled with before-after measurement of outcome variables. We randomly assigned 445 nurses working in 27 inpatient departments in a midsize hospital in Israel to experimental and control groups. Ten randomly chosen nurses in both groups filled a brief questionnaire referring to last conversation with head nurse. One month later, head nurses in the experimental group received individual feedback, comparing individual with mean hospital scores, coupled with self-set goals for the following feedback session. Head nurses in the control group received no feedback, except for a summary report by the end of intervention.

Results Patient care messages increased by 16% and professional development messages by 12%, accompanied by 17% decline in nurse-blaming messages in the experimental group, remaining unchanged in the control group. Such changes led to statistically significant increase in patient care behaviours (17%), safety climate (13%), teamwork (9%) and supervisory leadership quality (18%). Rule-compliance messages and workaround behaviours remained unchanged in experimental and control departments.

Conclusions These data support the utility of our intervention strategy for improving patient safety climate and resultant caring behaviours in healthcare organisations. The fact that our intervention used easy-to-deliver feedback requiring only two sessions minimised its organisational costs.