Value domain

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:

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.