title: Scoping review: The use of early warning systems for the identification of in-hospital patients at risk of deterioration.
abstract: BACKGROUND
  Early warning systems (EWS) were developed as a means of alerting medical staff to patient clinical decline. Since 85% of severe adverse events are preceded by abnormal physiological signs, the patient bed-side vital signs observation chart has emerged as an EWS tool to help staff identify and quantify deteriorating patients. There are three broad categories of patient observation chart EWS: single or multiple parameter systems; aggregated weighted scoring systems; or combinations of single or multiple parameter and aggregated weighted scoring systems.
  
  
  OBJECTIVE
  This scoping review is an overview of quantitative studies and systematic reviews examining the efficiency of the adult EWS charts in the recognition of in-hospital patient deterioration.
  
  
  METHODS
  A broad search was undertaken of peer-reviewed publications, official government websites and databases housing research theses, using combinations of keywords and phrases.
  
  
  METHODS
  CINAHL with full text; MedLine, PsycINFO, MasterFILE Premier, GreenFILE and ScienceDirect. Also, the Cochrane Library database, Department of Health government websites and Ethos, ProQuest and Trove databases were searched.
  
  
  METHODS
  Paediatric, obstetric and intensive care studies, studies undertaken at the point of hospital admission or pre-admission, non-English publications and editorials.
  
  
  RESULTS
  Five hundred and sixty five publications, government documents, reports and theses were located of which 91 were considered and 21 were included in the scoping review. Of the 21 publications eight studies compared the efficacy of various EWS and 13 publications validated specific EWS.
  
  
  CONCLUSIONS
  There is low level quantitative evidence that EWS improve patient outcomes and strong anecdotal evidence that they augment the ability of the clinical staff to recognise and respond to patient decline, thus reducing the incidence of severe adverse events. Although aggregated weighted scoring systems are most frequently used, the efficiency of the specific EWS appears to be dependent on the patient cohort, facilities available and staff training and attitude. While the review demonstrates support for EWS, researchers caution that given the contribution of human factors to the EWS decision-making process, patient EWS charts alone cannot replace good clinical judgment.
authors.affiliation: 313 Bourbong St, Mater Misericordiae Hospital Bundaberg, 4670 Queensland, Australia. Electronic address: marie.d.lelagadec@cqumail.com.
authors.forename: Marie Danielle
authors.initials: MD
authors.lastname: Le Lagadec
authors.affiliation: Building 18/G.06 Rockhampton, CQUniversity Australia, Bruce Highway, Rockhampton, Queensland 4702, Australia. Electronic address: t.dwyer@cqu.edu.au.
authors.forename: Trudy
authors.initials: T
authors.lastname: Dwyer
mesh_terms: D000328:Adult; D002983:Clinical Competence; D000075902:Clinical Deterioration; D016638:Critical Illness; D003657:Decision Making; D006760:Hospitalization; D006801:Humans; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D055986:Vital Signs
keywords: Early warning systems; In-hospital patients; Patient deterioration; Patient outcomes; Preventable mortality; Severe adverse events; Track-and-trigger; Unplanned ICU admission