title: Development and validation of a score to identify in the Emergency Department patients who may benefit from a time-critical intervention: a cohort study.
abstract: BACKGROUND
  Risk stratification methods developed on the basis of predicting illness severity are often used to prioritise patients on the basis of urgency. Illness severity and urgency may not be interchangeable. Severe illness places patients at risk of adverse outcome, but treatment is only urgent if adverse outcome can be prevented by time-sensitive treatment. We aimed to develop a score to identify patients in need of urgent treatment, on the basis of potential to benefit from time-sensitive intervention, and to compare this with a severity score identifying patients at high risk of death.
  
  
  METHODS
  A sequential cohort of adults presenting to one Emergency Department by ambulance and admitted to hospital was prospectively collected (2437 derivation, 2322 validation). Data on outcomes representing potential to benefit was collected retrospectively on a random subset (398 derivation, 227 validation). Logistic regression identified variables predictive of death and potential to benefit from urgent treatment.
  
  
  RESULTS
  Death was predicted using age, respiratory rate, diastolic blood pressure, oxygen saturations, temperature, GCS and respiratory disease (AUROC 0.84 (95 % CI 0.8-0.89) derivation and 0.74 (0.69-0.81) validation), while potential to benefit was predicted by pulse, systolic blood pressure and GCS (AUROC 0.74 (0.67-0.80) derivation and 0.71 (0.59-0.82) validation).
  
  
  CONCLUSIONS
  A score developed to predict the need for urgent treatment has a different composition to a score developed to predict illness severity, suggesting that triage methods based on predicting severity could lead to inappropriate prioritisation on the intended basis of urgency.
authors.affiliation: University of Sheffield, Regent Court, Regent Street, Sheffield, S1 4DA, UK. kirstychallen@hotmail.com.
authors.forename: Kirsty
authors.initials: K
authors.lastname: Challen
authors.affiliation: University of Sheffield, Regent Court, Regent Street, Sheffield, S1 4DA, UK. m.bradburn@sheffield.ac.uk.
authors.forename: Mike
authors.initials: M
authors.lastname: Bradburn
authors.affiliation: University of Sheffield, Regent Court, Regent Street, Sheffield, S1 4DA, UK. s.goodacre@sheffield.ac.uk.
authors.forename: Steve W
authors.initials: SW
authors.lastname: Goodacre
mesh_terms: D000367:Age Factors; D000368:Aged; D001794:Blood Pressure; D001831:Body Temperature; D004636:Emergency Service, Hospital / Q000458:organization & administration*; D004739:England; D005260:Female; D015600:Glasgow Coma Scale; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D010100:Oxygen / Q000097:blood; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011674:Pulse; D056152:Respiratory Rate; D012140:Respiratory Tract Diseases / Q000150:complications; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012720:Severity of Illness Index; D014218:Triage
chemical_list: D010100:Oxygen