title: Undertriage in the Manchester triage system: an assessment of severity and options for improvement.
abstract: BACKGROUND
  The Manchester Triage System (MTS) determines an inappropriately low level of urgency (undertriage) to a minority of children. The aim of the study was to assess the clinical severity of undertriaged patients in the MTS and to define the determinants of undertriage.
  
  
  METHODS
  Patients who had attended the emergency department (ED) were triaged according to the MTS. Undertriage was defined as a 'low urgent' classification (levels 3, 4 and 5) under the MTS; as a 'high urgent' classification (levels 1 and 2) under an independent reference standard based on abnormal vital signs (level 1), potentially life-threatening conditions (level 2), and a combination of resource use, hospitalisation, and follow-up for the three lowest urgency levels. In an expert meeting, three experienced paediatricians used a standardised format to determine the clinical severity. The clinical severity had been expressed by possible consequences of treatment delay caused by undertriage, such as the use of more interventions and diagnostics, longer hospitalisation, complications, morbidity, and mortality. In a prospective observational study we used logistic regression analysis to assess predictors for undertriage.
  
  
  RESULTS
  In total, 0.9% (119/13,408) of the patients were undertriaged. In 53% (63/119) of these patients, experts considered undertriage as clinically severe. In 89% (56/63) of these patients the high reference urgency was determined on the basis of abnormal vital signs. The prospective observational study showed undertriage was more likely in infants (especially those younger than three months), and in children assigned to the MTS 'unwell child' flowchart (adjusted OR<3 months 4.2, 95% CI 2.3 to 7.7 and adjusted ORunwell child 11.1, 95% CI 5.5 to 22.3).
  
  
  CONCLUSIONS
  Undertriage is infrequent, but can have serious clinical consequences. To reduce significant undertriage, the authors recommend a systematic assessment of vital signs in all children.
authors: Department of Paediatrics, Erasmus MC-Sophia Children's Hospital, University Medical Centre Rotterdam, Rotterdam, The Netherlands.
authors: N
authors: N
authors: Seiger
authors: M
authors: M
authors: van Veen
authors: E W
authors: EW
authors: Steyerberg
authors: M
authors: M
authors: Ruige
authors: A H J
authors: AH
authors: van Meurs
authors: H A
authors: HA
authors: Moll
mesh_terms: D000293:Adolescent; D001794:Blood Pressure / Q000502:physiology; D002648:Child; D002662:Child Health Services / Q000592:standards*; D002675:Child, Preschool; D004630:Emergencies; D004636:Emergency Service, Hospital / Q000592:standards*; D005260:Female; D006295:Health Resources / Q000706:statistics & numerical data; D006302:Health Services Research; D006339:Heart Rate / Q000502:physiology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009426:Netherlands; D018579:Patient Selection; D011446:Prospective Studies; D056152:Respiratory Rate / Q000502:physiology; D012720:Severity of Illness Index; D014218:Triage / Q000379:methods / Q000592:standards*