Health boards and trusts are required to calculate the number and skill mix of nursing staff required to meet the needs of patients by triangulating three critical sources of knowledge:
- patient acuity: an estimate of the amount of care a patient requires based on the intensity, complexity and unpredictability of their holistic needs. In Wales the Welsh Levels of Care is the tool used to assist nurses in measuring the acuity and dependency of their patients.
- quality indicators: a measure of factors that relate to the delivery of nursing care and are used to demonstrate whether the department delivers good outcomes for patients and staff.
- professional judgement: involves the nurse applying their knowledge, skills and experience in a way which is informed by professional standards, law and ethical principles to develop a decision on the factors which influence clinical decision making in relation to patient safety.