title: Does the use of a "track and trigger" warning system reduce mortality in trauma patients?
abstract: BACKGROUND
  Despite the lack of robust evidence, numerous different "track and trigger" warning systems have been implemented. These have only been validated in an emergency medical admissions setting. The Modified Early Warning Score (MEWS) is the chosen track and trigger system used in the University Hospitals of Leicester trauma unit, but has not been validated in trauma patients. A considerable proportion of all trauma admissions are elderly patients with proximal femoral fractures and significant co-morbidities. Early recognition of physiological deterioration and prompt action could therefore be lifesaving in this patient group.
  
  
  OBJECTIVE
  To identify whether the implementation of the MEWS system coupled with a critical care outreach service resulted in a reduction in mortality in a busy trauma unit.
  
  
  METHODS
  A retrospective study. The MEWS system was implemented in all trauma and orthopaedic wards at the Leicester Royal Infirmary in the summer of 2005. The numbers of emergency trauma inpatient admissions and deaths from January 2002 to December 2009 were obtained. The diagnosis, primary procedures and cause of death, if known, were noted. Comparisons were made pre- and post-MEWS. Student's t-test was used for statistical analysis.
  
  
  RESULTS
  32,149 patients were admitted (55% male; 45% female). Overall there were 889 deaths (77% female; 33% male, P<0.0001). The in-hospital mortality rate for orthopaedic trauma patients was 2.8% throughout the 7-year study period. 61% of those who died were admitted with proximal femoral fractures. The modal age group with the highest mortality was 81-90 years. Overall, females had a considerably greater mortality rate than males. The mortality rate was lower post-MEWS in males (1.82-1.418%; P=0.214), females (4.871-3.364%; P=0.108) and all patients (3.215-2.294%; P=0.092), but this was not statistically significant.
  
  
  CONCLUSIONS
  The use of a track and trigger warning system has not led to a statistically significant reduction in mortality in trauma patients. In view of the apparent lack of clinical effectiveness of the MEWS/outreach partnership, the cost effectiveness of this initiative needs to be questioned. Possible reasons for these findings include: failure of the MEWS to be correctly applied, inadequate action once the threshold is triggered, or unsuitability of this tool for this patient population. A better system for identifying and treating elderly, medically unwell trauma patients with co-morbidities needs to be developed.
authors.affiliation: Trauma and Orthopaedic Department, Leicester General Hospital, Gwendolen Road, Leicester, LE5 4PW, United Kingdom. Shaqs@doctors.org.uk
authors.forename: M S
authors.initials: MS
authors.lastname: Patel
authors.forename: M A
authors.initials: MA
authors.lastname: Jones
authors.forename: M
authors.initials: M
authors.lastname: Jiggins
authors.forename: S C
authors.initials: SC
authors.lastname: Williams
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D042241:Early Diagnosis; D005260:Female; D006620:Hip Fractures / Q000401:mortality; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008875:Middle Aged; D015397:Program Evaluation; D012189:Retrospective Studies; D017678:Sex Distribution; D014193:Trauma Centers / Q000706:statistics & numerical data*; D055986:Vital Signs / Q000502:physiology; D014947:Wounds and Injuries / Q000401:mortality*; D055815:Young Adult