The impact of the use of the Early Warning Score (EWS) on patient outcomes: A systematic review

• Published in: Resuscitation 2014-05, Vol.85 (5), p.587-594
• Main Authors: Alam, N, Hobbelink, E.L, van Tienhoven, A.J, van de Ven, P.M, Jansma, E.P, Nanayakkara, P.W.B
• Format: Article
• Language: English
• Subjects: Clinical outcomes; Critical Care - utilization; Critical Illness - mortality; Deteriorating patients; Disease Progression; Early Warning Score; Emergency; Heart Arrest - mortality; Hospital Mortality; Humans; Length of Stay - statistics & numerical data; Monitoring; Monitoring, Physiologic - methods; Outreach service; Physiological parameters; Treatment Outcome
• ISSN: 0300-9572; 1873-1570
• DOI: 10.1016/j.resuscitation.2014.01.013

Abstract Background Acute deterioration in critical ill patients is often preceded by changes in physiological parameters, such as pulse, blood pressure, temperature and respiratory rate. If these changes in the patient's vital parameters are recognized early, excess mortality and serious adverse events (SAEs) such as cardiac arrest may be prevented. The Early Warning Score (EWS) is a scoring system which assists with the detection of physiological changes and may help identify patients at risk of further deterioration. Objectives The aim of this systematic review is to evaluate the impact of the use of the Early Warning Score (EWS) on particular patient outcomes, such as in-hospital mortality, patterns of intensive care unit admission and usage, length of hospital stay, cardiac arrests and other serious adverse events of adult patients on general wards and in medical admission units. Design and setting Systematic review of studies identified from the bibliographic databases of PubMed, EMBASE.com and The Cochrane Library. Selection criteria All controlled studies which measured in-hospital mortality, ICU mortality, serious adverse events (SAEs), cardiopulmonary arrest, length of stay and documentation of physiological parameters which used a EWS on the ward or the emergency department to identify patients at risk were included in the review. Data collection and analysis Three reviewers (NA, AT and EH) independently screened all potentially relevant titles and abstracts for eligibility, by using a standardized data-worksheet. Meta-analysis was not possible due to heterogeneity. Main results Seven studies met the inclusion criteria. The results of our included studies were mixed, with a positive trend towards better clinical outcomes following the introduction of the EWS chart, sometimes coupled with an outreach service. Six of the seven included studies used mortality as an endpoint: two of these studies reported no significant difference in in-hospital mortality rate; two found a significant reduction of in-hospital mortality; two other studies described a trend towards improved survival. Although, both ICU mortality and serious adverse events were not significantly improved, there was a trend towards reduction of these endpoints after introduction of the EWS. However only two studies looked respectively at each endpoint. There were conflicting results concerning cardiopulmonary arrests. One study found a reduction in the incidence of cardiac arrest calls