Patient safety and quality assurance is a priority across all components of the Irish healthcare system. Acute physiological deterioration is a time-critical medical emergency that affects millions of people worldwide. Early Warning Systems (EWS) (also termed ‘Track-and-trigger systems’) have been established in acute care clinical settings to facilitate a timelier response to, and assessment of, acutely ill patients by:
1. Classifying the severity of a patient’s illness;
2. Providing prompts and structured communications tools to escalate care;
3. Following a definitive escalation plan.
Standardization of early warning scores optimizes organizational delivery of safe, equitable and quality care for all acutely ill patients. Such standardization has been achieved through national consensus and the publication of national guidelines.
As specified by the Department of Health National Clinical Effectiveness Unit the aim of this project was to complete an update of a systematic review of the clinical and economic literature on early warning scores/systems or trigger systems used in adult (non-pregnant) patients in acute healthcare settings for the detection of/timely identification of physical, clinical deterioration.
A full search strategy was developed by the research team to include key terms and their variations. Key terms included a combination of terms associated with “early warning scoring systems”; such terms were associated with the PICOS (Patient/Problem, Intervention, Comparison, Outcome, Setting) guidance framework. The published literature was identified by searching the pertinent electronic databases and selected grey literature. These included: Academic Search Complete, CINAHL (the Cumulative Index to Nursing and Allied Health Literature), Medline, PsycINFO, PsycARTICLES, Psychology and Behavioral Science Collection, SocINDEX, and UK/Eire Reference Centre), Cochrane library, Guideline Websites, Business Source Complete, EconLit and NHS Economic Evaluation Database (NHS EED).
All evidence sourced was graded according to Scottish Intercollegiate Guidelines Network (SIGN) level of evidence (LOE) criteria and associated methodological checklists which looked at internal validity and overall assessment of the study for each study type.
One hundred and twenty four (n=124) empirical and 5 economic papers were included in the clinical and economic reviews respectively. The majority (92.7%) of the clinical evidence was categorised as ≤2+ LOE categorisation using SIGN criteria.
Within the systematic review, a variety of EWSs were sourced. Even within each system there were differences in the vital sign scoring and the weighting assigned to scores when they were used in different studies/hospitals/subpopulations. This made comparisons difficult. However, this review summarises evidence that demonstrates that NEWS has been shown to be an effective assessment tool to identify and triage the patient for the most appropriate acute care assessments and interventions. The studies reviewed also identified that timely escalation remains an ongoing problem. Thus understanding the organisational culture, systems, practices, barriers and facilitators and the stakeholders’ perceptions and interactions with the NEWS is important.
An Early Warning System is a multi-component complex system as illustrated in Figure 1. Most studies reviewed failed to take into account that the overall performance of the system depends on the performance of its individual parts, and the individuals interacting with it which makes the interpretation of results difficult. High levels of adherence and consistent adherence are necessary for the system to be effective. Many similarities exist across guidance internationally pertaining to the early recognition of the deteriorating patient. What is clear is the movement towards using a whole systems approach whilst placing governance at the centre in the maintenance of organisation-wide recognition and response systems. Such systems require the utilisation of data from the evaluation of EWS to inform quality improvement activities.
Empowering health care professionals to act on their clinical judgment is also a critical component of any system introduced. Across international guidelines the concept of patients in high EWS trigger groups requiring immediate action/review by individual(s) with critical care competencies and diagnostic skills was very evident.
The importance of multi-format, inter-professional training, regular reinforcement, case reviews and an interactive- in person training process was reiterated in a number of studies that explored educational interventions.
Given the absence of higher level evidence (e.g. trials, high quality case control or cohort or studies) in the research literature sourced, it is important that research be conducted in tandem with the implementation of EWS systems with particular emphasis on the application of EWS to subgroups (e.g. older adults) and particular contexts of care (e.g. ED).