The relationship between nurse staffing levels and patient outcomes: A scoping review of the evidence from high-income countries.
Aims This dissertation aims to explore the relationship between nurse staffing levels and patient outcomes. It proposes to summarise the evidence regarding this link and expose and discuss the gaps and limitations in these studies. Background As healthcare has developed, quality of care has become a focal problem for the healthcare system and nurses. Increasing concerns about patient outcomes and the quality of care have resulted in several studies, focused on identifying adequate nurse staffing levels and the relationship between nurse staffing and quality of care. An extensive amount of literature over the last 10 years reports the importance of the role of nurses and their duty to provide safe, good quality care and the relationship between low nurse staffing levels and adverse patient outcomes, for example: falls, missed care and even death. Despite the size of the existing evidence, there are numerous limitations in these studies that have not been reported extensively. Amongst these gaps is the theory of endogeneity, which is a form of bias that occurs when estimating causal effects between variables. While there are no discrepancies in current literature about the causal pathway between nurse staffing and patient outcomes, endogeneity points to the fact that the scope of the effects may be biased or incorrect. This topic is of great importance, as the research is still unclear about what constitutes as adequate nurse staffing levels that will promote high-quality patient outcomes. Design Scoping review to synthesise existing knowledge in the literature on the relationship between nurse staffing levels and patient outcomes. Methods 29 primary studies conducted in hospitals in high income countries were reviewed between 2008 and 2018. Findings Numerous gaps were found in the literature. This scoping review found that most of the current evidence did not discuss the forms of bias that could affect the causal path between nurse staffing and patient outcomes. Overall, the evidence shows an increase in nurse staffing levels has a positive effect on patient outcomes. However, a majority of the studies showed that although nurse staffing levels were vital to patients’ safety, there were other confounding factors that mediated this relationship or by themselves had a strong impact on patient outcomes. Conclusion As previous research suggests, this paper confirms that there is a indeed a correlation between nurse staffing levels and patient outcomes. However, many studies have also revealed that nurse staffing is not the only variable involved in patient outcomes. More research is warranted, to identify other variables that affect patient outcomes, so that recommendations can be made for policy and guidelines will be able to assure the best possible care is provided. Keywords Nurse staffing, patient outcomes, relationship