• Bayesian network;
  • nurse staffing;
  • outcomes;
  • registered nurse;
  • survey

Aim  The aim of the present study was to assess the relationship between patient-to-registered nurse (RN) ratios and nursing outcomes: job satisfaction and stress, nursing care quality, control of own practise, intent to leave, adequacy of material resources and attitudes towards technical equipment.

Background  Although there is a growing body of evidence showing that higher levels of RN staffing are linked to better outcomes, it still is unclear how nurse staffing produces these effects.

Method  A survey of data of RNs (n = 854) in 46 inpatient units at five university hospitals in Finland was used to create a Bayesian network (BN) model of connections between the variables.

Results  A BN model constructed showed that the quality of nursing care is influenced by multifaceted work environment measures. RNs’ possibility to control their own practice and the quality of care are mediation between patient-to-RN ratio and other variables examined.

Conclusions  New insight was given to the complex theme of the nursing practice environment and its connections to nursing outcomes.

Implications for nursing management  Work environment should be developed with consideration of many factors, including adequate staffing levels and the ability for nurses to control their own work. This could increase nurses’ work satisfaction, retention and patient care quality outcomes.