Ways of representing data:
Stand alone value with units
Relative to a reference value or range (above normal; low-normal-high)
Z-score (incorporating mean and SD)
Multiple of mean (MOM)
Multiple of upper limit of normal (ULN)
Classification of Data Items
(1) simple vs complex (structure)
(2) constant vs variable/changing
(3) predictable vs unpredictable
(4) situational
Query: Does the person have a history of heart disease?
Simple response: Yes or No.
Complex data structure: date of occurrence, anatomic distribution, severity
Date of birth is constant.
Age is constantly changing at a rate of 1 per year.
Blood pressure changes but not in a constant manner.
Predictability: if a patient is normal, then the measure should be within a defined range.