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The date of birth of the person, expressed as DDMMYYYY.


Data Element (this item)


This representation is based on the value domain for this data element, more information is available at " Date DDMMYYYY ".
Data Type Date/Time
Maximum character length 8


Guide for use:

If date of birth is not known or cannot be obtained, provision should be made to collect or estimate age. Collected or estimated age would usually be in years for adults, and to the nearest three months (or less) for children aged less than two years. Additionally, an estimated date flag or a date accuracy indicator should be reported in conjunction with all estimated dates of birth.

For data collections concerned with children's services, it is suggested that the estimated date of birth of children aged under 2 years should be reported to the nearest 3 month period, i.e. 0101, 0104, 0107, 0110 of the estimated year of birth. For example, a child who is thought to be aged 18 months in October of one year would have his/her estimated date of birth reported as 0104 of the previous year. Again, an estimated date flag or date accuracy indicator should be reported in conjunction with all estimated dates of birth.


National Health Data Committee

National Community Services Data Committee


Privacy issues need to be taken into account in asking persons their date of birth.

Wherever possible and wherever appropriate, date of birth should be used rather than age because the actual date of birth allows a more precise calculation of age.

When date of birth is an estimated or default value, national health and community services collections typically use 0101 or 0107 or 3006 as the estimate or default for DDMM.

It is suggested that different rules for reporting data may apply when estimating the date of birth of children aged under 2 years because of the rapid growth and development of children within this age group which means that a child's development can vary considerably over the course of a year. Thus, more specific reporting of estimated age is suggested.


AS5017 Health Care Client Identification, 2002, Sydney: Standards Australia

AS4846 Health Care Provider Identification, 2004, Sydney: Standards Australia

This content Based on Australian Institute of Health and Welfare material. Attribution provided as required under the AIHW CC-BY licence.

Related content

Relation Count
Input in Derivations 1
Output in Derivations 0
Inclusion in Data Set Specifications 137
Inclusion in Data Distributions 1
As a numerator in an Indicator 39
As a denominator in an Indicator 10
As a disaggregation in an Indicator 11