A value domain is the set of permitted values which a data element can use. Value domains can be enumerated (with lists of permissible answers, specified as codes) or non-enumerated (described with ranges of allowed values). They basically describe what the ‘valid answers’ are for a given data element. There are over 1,400 value domains in METEOR.
Most value domains are enumerated. Some examples are:
- Type of permanent care arrangement code N[N], where a value of 1 = Reunification with birth parents, a value of 2 = Reunification with relatives/kin other than birth parents, and so on.
- Diabetes mellitus status code NN, where a value of 01 = Type 1 diabetes, a value of 02 = Type 2 diabetes, 03 = Gestational diabetes mellitus, and so on.
- Marital status code N, where a code of 1 = Never married, 2 = Widowed, 3 = Divorced, and so on.
- Pharmaceutical Benefits Scheme (PBS) item code NN[NNN]A, which is a code set of all the medicinal and therapeutic products included in the Schedule of Pharmaceutical Benefits, which is the classification scheme for this value domain.
Some non-enumerated value domains are:
- Date DDMMYYYY, where the value is a date expressed as 2 digits for day, 2 digits for month, and 4 digits for year.
- Medicare card number identifier N(11), where the value is an 11-digit long number.
- Time hhmm, where the value is a time on a 24-hour clock expressed as 2 digits for hours, and 2 digits for minutes.
When a value domain is combined with a data element concept, they create a data element.
For example the data element Person—student type, code N is made from the data element concept Person—student type with the value domain Student type code N, which lists the available options as codes: 1 = Preschool student, 2 = Primary school student, 3 = Secondary school student, and so on.
One particular data element concept can be combined with a range of value domains to create different data elements. For example, the Person–age range, code NN has the codes 1 = 0–4 (years), 2 = 5–14, and so on, while in the data element Person—age range, code N, the code 1 = Under 18 years, and 2 = 18 to 24 years, and so on.