Safe Staffing in Accident and Emergency Departments: A Systematic Review of the Literature

Aim of review The aim of the review was to identify the evidence base for safe nurse staffing in A&E departments by examining the impact of variation in staffing and approaches to determining staffing on patient and nurse... [ view full abstract ]

Aim of review
The aim of the review was to identify the evidence base for safe nurse staffing in A&E departments by examining the impact of variation in staffing and approaches to determining staffing on patient and nurse outcomes and the impact of variation in relevant factors on measured staffing requirements. The review was undertaken on behalf of the National Institute for Health and Care Excellence (NICE).

Search and review methodology
A systematic review of relevant primary material was conducted. The protocol and methods adopted were in accordance with Developing NICE Guidelines. A quality appraisal checklist was used to assess the internal and external validity of the studies. Due to the majority of the studies reviewed being cross-sectional/observational in design, the appraisal checklist was designed to match the specifics of these studies.

Findings
There is inconsistent evidence from observational studies, the majority with poor validity that associates ED staffing levels with patient outcomes. The evidence regarding patient waiting times and time to antibiotics for patients diagnosed with pneumonia is inconsistent. The inconsistency may be explained by differences in study designs and how nurse-patient ratios were operationalized; however, there is evidence that higher rates of ED staffing are associated with decreased levels of patients leaving an ED without being seen, and reduced emergency department care time. No association was found between ED nurse staffing medication errors, time to antibiotics or patients’ length of stay.

Conclusions
The evidence reviewed identified a number of outcomes that were associated with nurse staffing levels in A&E departments. There was consistency in the studies reviewed that explored the association between staffing levels and patients leaving the ED without being seen. The primarily observational studies we found often had a high risk of bias from unmeasured confounding or endogeneity between staffing levels and the outcome. Although the review identified relationships between nurse staffing in the A&E and outcomes such as patients leaving without being seen and waiting times, there was a lack of evidence on the impact of safe staffing on outcomes such as mortality, failure to rescue, never events, time to pain assessment or falls.