Nursing staff numbers and their relationship to conflict and containment rates on psychiatric wards-a cross sectional time series poisson regression study.

BACKGROUND: The link between positive outcomes and qualified nurse staffing levels is well established for general hospitals. Evidence on staffing levels and outcomes for mental health nursing is more sparse, contradictory and complicated by the day to day allocation of staff resources to wards with more seriously ill patients.
OBJECTIVE: To assess whether rises in staffing numbers precede or follow levels of adverse incidents on the wards of psychiatric hospitals.
DESIGN: Time series analysis of the relationship between shift to shift changes over a six month period in total conflict incidents (aggression, self-harm, absconding, drug/alcohol use, medication refusal), total containment incidents (pro re nata medication, special observation, manual restraint, show of force, time out, seclusion, coerced intramuscular medication) and nurse staffing levels. SETTINGS: 32 acute psychiatric wards in England.
METHODS: At the end of every shift, nurses on the participating wards completed a checklist reporting the numbers of conflict and containment incidents, and the numbers of nursing staff on duty.
RESULTS: Regular qualified nurse staffing levels in the preceding shifts were positively associated with raised conflict and containment levels. Conflict and containment levels in preceding shifts were not associated with nurse staffing levels.
CONCLUSIONS: Results support the interpretation that raised qualified nurse staffing levels lead to small increases in risks of adverse incidents, whereas adverse incidents do not lead to consequent increases in staff. These results may be explicable in terms of the power held and exerted by psychiatric nurses in relation to patients.