• Accreditation
• Ambulatory care
• Anaesthesia

In hospitals, the nursing staff typically represent the largest single element of cost, and nursing is frequently treated as a cost centre rather than a core service line. Efforts to contain hospital costs often involve cutting nursing care, reducing the number of nurses or replacing some professional nursing staff with staff such as licensed practical nurses, nurses' aides and other assistive personnel.

Substantial evidence from studies in the USA, Europe and other countries relates lower nurse staffing and higher nurse workloads to adverse patient outcomes such as mortality, infections, falls and longer lengths of stay. Longer stays, which increase hospital costs, may result from increased adverse events lengthening admissions or delays in care due to nurses being unable to complete their work or prepare patients for discharge.1–13

The consequences of relying more heavily on staff less educated than the professional nurse, using a lower skill mix, remain less well studied. Studies from the USA and Canada, often focusing on the mix of professional nurses (registered nurses) and licensed practical nurses have consistently found lower skill mix to also be associated with higher rates of adverse outcomes and longer length of stay.7 ,14–17

Aiken et al18 examine the association of skill mix with mortality, patient ratings of hospitals, nurse-reported frequency of adverse patient outcomes and nurse job dissatisfaction and burnout, using data from hospitals in six European countries. They find substantial variation across medical-surgical units in the proportion of professional nurses among direct care nursing personnel (which include professional nurses, licensed practical nurses, nursing assistants and other job categories that vary across their six country sample) and that this variation in skill mix is associated with patient mortality, patient perceptions of care and nurse judgements of quality and frequency of adverse outcomes.

A strength of this study …