[WWW - 2021.12.16]
Identifying and Definitional Attributes
QH 040163
Metadata Item Type
Data Element
Data Element Type
Data Element
Approval Status
Approval Type
Approving Authority
Effective From
Effective To
The date of birth of the person.
Required for a range of clinical and administrative purposes. Date of birth enables derivation of age for use in demographic analyses, assists in the unique identification of clients if other identifying information is missing or in question, and may be required for the derivation of other data elements (e.g. Diagnosis related group for admitted patients).
Short Name
Date of birth
Name in Other Contexts
Representational Attributes
Numeric character
Representation Class
Minimum Character Length
Maximum Character Length
Permissible Values
Valid date
Supplementary Values
Collection and Usage Attributes
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 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 should be reported in conjunction with all estimated dates of birth.
Verification Rules
In data collections that also record Date of death for the same person, Date of birth must be less than or equal to Date of death.
Collection Methods
Information on Date of birth can be collected using the one question:

What is your/(the person's) date of birth? In self-reported data collections, it is recommended that the following response format is used:
Date of birth:  _ _ / _ _ / _ _ _ _
This enables easy conversion to the preferred representational layout (DDMMYYYY).

Estimated dates of birth should be identified by an appropriate estimated date flag to prevent inappropriate use of Date of birth data for record identification and/or the derivation of other data elements that require accurate date of birth information.

NHDD specific- Perinatal NMDS:
Data collection systems must be able to differentiate between the date of birth of the mother and the baby(s). This is important in the Queensland Perinatal data collection as the date of birth of the baby is used to determine the antenatal length of stay and the postnatal length of stay.

NHDD specific - Health care client identification DSS and Health care provider identification DSS:
Where any component of the Date of birth is not known, provision should be made to collect age (in years) and a year of birth derived from age. 

The linking of client records from diverse sources, the sharing of patient data, and data analysis for research and planning all rely heavily on the accuracy and integrity of the collected data. In order to maintain data integrity and the greatest possible accuracy an indication of the accuracy of the date collected is critical. For this reason it is strongly recommended that the data element Date accuracy indicator also be recorded at the time of record creation to flag the accuracy of the data. 

In some instances, the collection of Date accuracy indicator may be essential in confirming or refuting the positive identification of a person.
This metadata item is common to both the National Community Services Data Dictionary and the National Health Data Dictionary.

Privacy issues need to be taken 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 more precise calculation of age. When Date of birth is 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.

NHDD specific: DSS Cardiovascular disease (clinical)
Age is an important non-modifiable risk factor for cardiovascular conditions. The prevalence of cardiovascular conditions increases dramatically with age. For example, more than 60% of people aged 75 and over had a cardiovascular condition in 1995 compared with less than 9% of those aged under 35. Aboriginal and Torres Strait Islander peoples are more likely to have cardiovascular conditions than other Australians across almost all age groups. For example, in the 25-44 age group, 23% of Indigenous Australians reported cardiovascular conditions compared with 16% among other Australians (Heart, Stroke and Vascular Diseases: Australian Facts 2001. AIHW).

Other References:
AS5017 Health Care Client Identification, 2002, Sydney: Standards Australia
	AS4846 Health Care Provider Identification, 2004, Sydney: Standards Australia
Relational Attributes
Related Metadata References
Is qualified by Date-accuracy indicator QH 040907 Version 1
Is used in conjunction with Time of birth QH 040160 Version 1
Supersedes Date of birth-client QH 040163 Version 1
Implementation in Metadata Sets


  • 1 - 4
ViewMetadata Item TypeMetadata Set TypeNameAscendingIdentifier & VersionObligationEffective FromEffective To
Information AssetData CollectionElective Surgery Data Collection (ESDC)QH 020110 Version 1Mandatory01-Jul-200430-Jun-2009
Information AssetData CollectionEmergency Data Collection (EDC)QH 020159 Version 1Mandatory01-Jul-200430-Jun-2009
Information AssetData CollectionQueensland Hospital Admitted Patient Data Collection (QHAPDC)QH 020001 Version 1Mandatory01-Jul-200430-Jun-2009
Information AssetData CollectionQueensland Perinatal Data Collection (QPDC)QH 020003 Version 1Mandatory01-Jul-200430-Jun-2009
Data Quality Declaration
Source and Reference Attributes
Source Organisation
Australian Institute of Health and Welfare
Source Document
METeOR data element: Person-date of birth, DDMMYYYY, Identifier 287007, Health standard 04/05/2005 https://meteor.aihw.gov.au/content/index.phtml/itemId/287007/meteorItemView/long

Date of birth