College of American Pathologists
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  Using dimensional modeling to create a
  laboratory data warehouse


CAP Today




July 2008

Facts—What is it that we want to be able to slice and dice? These are our facts (measures):
  • Average glucose
  • Number of glucose measurements
  • Average minutes to upload
  • Average number of measures per day/patient
  • Number of patients
  • Length of stay
Attributes—What are the ways in which we want to be able to slice and dice our facts? These are our attributes:
  • Patient location
  • Discharge diagnosis
  • Race
  • Nursing shift
  • Patient age
  • Year…month…day
  • Mortality
  • Patient service
  • Length of stay
  • Results
Dimensions—Attributes are grouped naturally into what become dimensions
  • Collection date
       year, month, day, weekday, holiday
  • Patient
        MRN, age, sex, race
  • Location
        room, unit, floor, wing, building
  • Admission
        LOS, mortality, diagnoses, cost