title: Developing emergency department physician shift schedules optimized to meet patient demand.
abstract: OBJECTIVE
  1) To assess temporal patterns in historical patient arrival rates in an emergency department (ED) to determine the appropriate number of shift schedules in an acute care area and a fast-track clinic and 2) to determine whether physician scheduling can be improved by aligning physician productivity with patient arrivals using an optimization planning model.
  
  
  METHODS
  Historical data were statistically analyzed to determine whether the number of patients arriving at the ED varied by weekday, weekend, or holiday weekend. Poisson-based generalized additive models were used to develop models of patient arrival rate throughout the day. A mathematical programming model was used to produce an optimal ED shift schedule for the estimated patient arrival rates. We compared the current physician schedule to three other scheduling scenarios: 1) a revised schedule produced by the planning model, 2) the revised schedule with an additional acute care physician, and 3) the revised schedule with an additional fast-track clinic physician.
  
  
  RESULTS
  Statistical modelling found that patient arrival rates were different for acute care versus fast-track clinics; the patterns in arrivals followed essentially the same daily pattern in the acute care area; and arrival patterns differed on weekdays versus weekends in the fast-track clinic. The planning model reduced the unmet patient demand (i.e., the average number of patients arriving at the ED beyond the average physician productivity) by 19%, 39%, and 69% for the three scenarios examined.
  
  
  CONCLUSIONS
  The planning model improved the shift schedules by aligning physician productivity with patient arrivals at the ED.
authors.affiliation: *Northern Ontario School of Medicine,Lakehead University,Thunder Bay,ON.
authors.forename: David W
authors.initials: DW
authors.lastname: Savage
authors.affiliation: †Department of Mathematics,Wilfrid Laurier University,Waterloo,ON.
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Woolford
authors.affiliation: *Northern Ontario School of Medicine,Lakehead University,Thunder Bay,ON.
authors.forename: Bruce
authors.initials: B
authors.lastname: Weaver
authors.affiliation: *Northern Ontario School of Medicine,Lakehead University,Thunder Bay,ON.
authors.forename: David
authors.initials: D
authors.lastname: Wood
mesh_terms: D001071:Appointments and Schedules; D004636:Emergency Service, Hospital / Q000458:organization & administration*; D006301:Health Services Needs and Demand / Q000458:organization & administration*; D006801:Humans; D017146:Models, Organizational; D009864:Ontario; D010820:Physicians / Q000706:statistics & numerical data*; D016526:Workload / Q000706:statistics & numerical data*
keywords: physician scheduling