The following information is applicable to value domains only.
Definition
The class of representation of a value domain (e.g. 'Code' or 'Total').
Obligation
Mandatory completion.
Development rules
Valid representation classes are presented in Table 1.
The representation class reflects the main structure of the value domain, not supplementary code(s) such as '99 - not stated/inadequately described'. For example, the representation class for a value domain permitting a measured value (e.g. 5 centimetres) or a '99.9 - not able to be measured' code is Total, not Code.
A value domain that is of representation class Ratio consists of measures of at least two distinct concepts, each of which may be collected in its own right e.g. body mass index is calculated from measures of a person’s body weight and body height. In contrast, a value domain that is of representation class Total is either an absolute count of something, reported in one or more units (e.g. Australian currency), or one measure, expressed as a proportionate quantity (e.g. milligrams per litre).
Sub-type classes of the Total representation class are available for optional use (i.e. Count, Currency and Quantity).
Table 1: Valid representation class values and their associated meanings
Value
Meaning
Average
A numeric value representing an arithmetic mean.
Code
A system of valid symbols that substitute for longer values.
Date
A numeric value representing a calendar date (i.e. day, month and year) or recognised part of a calendar date (i.e. day, month, and/or year).
Identifier
A value which establishes identity.
Percentage
Parts per hundred.
Ratio
An expression of the quantity of one substance or entity in relation to that of another (Dorlands, 2003: 1586).
Text
An unformatted, descriptive value.
Time
A numeric value representing a specific instance in time.
Total
A numeric value representing the sum of a set of values or an entire quantity (including monetary).
Count
A numeric value representing a non-monetary numeric value arrived at by counting.
Currency
A numeric value representing a monetary value.
Quantity
A numeric value representing a continuous number such as the linear dimensions, capacity/amount (non-monetary) of an object.