title: Pilot study of metropolitan emergency department workload complexity.
abstract: OBJECTIVE
  Assessment of emergency department (ED) patient complexity using the number of procedures, investigations or consultations (PICsum).
  
  
  METHODS
  Retrospective analysis of 12 months of data from an adult metropolitan teaching hospital ED.
  
  
  RESULTS
  A bimodal distribution of PICsum (modal peaks, PICsum 1 and 7) was observed in all Australasian Triage Scale, disposition, mode of arrival, age and referral source groups. Patients requiring a minimum of two procedures or a minimum of two investigations or a minimum of two consultations (Min2 patients) comprised 59% (95% CI 58.5-59.5) of total patients 93% (95% CI 92.5-93.8) of total PICsum. Age is highly correlated with Mean PICsum (Pearson r = 0.98, P < 0.001) and the proportion of Min2 patients (Pearson r = 0.98, P < 0.001).
  
  
  CONCLUSIONS
  An intuitive partition in the complexity distribution is identified at up to one procedure, one investigation and one consultation. Patient age is correlated with complexity and ED age distribution may be a useful proxy for complexity, particularly if used in conjunction with validated age versus complexity tables.
authors.affiliation: Acute Demand Management Unit, State Health Emergency Services, Health Department of Western Australia, Fremantle, Australia. peter.sprivulis@health.wa.gov.au
authors.forename: Peter
authors.initials: P
authors.lastname: Sprivulis
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003953:Diagnosis-Related Groups / Q000706:statistics & numerical data*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D004638:Emergency Treatment / Q000706:statistics & numerical data*; D005240:Feasibility Studies; D006302:Health Services Research; D006784:Hospitals, Teaching / Q000706:statistics & numerical data*; D006786:Hospitals, Urban / Q000706:statistics & numerical data*; D006801:Humans; D016014:Linear Models; D008875:Middle Aged; D010865:Pilot Projects; D012017:Referral and Consultation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014187:Transportation of Patients / Q000706:statistics & numerical data; D014218:Triage / Q000706:statistics & numerical data; D014904:Western Australia; D016526:Workload / Q000706:statistics & numerical data*