Record linkage at Statistics Canada

What is record linkage?
Conditions and approvals for linkages
Types of linkages
List of approved linkages

What is record linkage?

Record linkage is the bringing together for statistical and research purposes of information about individual respondents or units of observation such as persons, households of businesses from two or more different sources in order to form combined individual micro records. Record linkage is a potentially important source of valuable statistical information, for example, to shed light on the effectiveness of certain cancer screening methods or the long-term effects of heart surgery.

Conditions and approvals for linkages

Statistics Canada will carry out linkages of different records pertaining to the same individual only for statistical purposes and only when the results of the linkage would yield a potential public good which clearly outweighs the potential invasion of the privacy rights of individuals included in the linkage. This activity is conducted in accordance with the Agency's Policy on Record Linkage which has been in place since 1986. All record linkage proposals must satisfy a prescribed review and approval process which involves the submission of documented proposals to an internal expert committee.

The recommendations of the review committee are forwarded to the Chief Statistician who refers for ministerial approval all recommendations he supports and which represent types of linkages not previously approved by the Minister. The Chief Statistician may also consult with the Office of the Privacy Commissioner and, in some instances, public interest groups and members of the public when considering types of linkages not previously approved by the Minister. It is the Minister who applies the ultimate judgement regarding the trade-off between the expected public benefit and the degree of privacy invasion which may be involved. The public dissemination of information resulting from record linkages, like all other statistical information, is done only in such as way as to ensure that no individual can be identified.

Types of linkages

There are two major categories of linkages conducted by Statistics Canada:

• linkages whose objective is to support the design, maintenance, evaluation, research and re-design of ongoing data collection and methodological studies within the Agency, and
• linkages whose objective is to provide statistical information inaggregate or anonymous format in support of research studies.

A description of the individual files containing personal information that are used in these linkages will be found in Info Source: Sources of Federal Government Information. Where the data files produced from the linkages constitute Personal Information Banks, they are registered and a description included in Info Source. In some cases, the individual merged files produced from the linkages are retained only until such time as tabulations in aggregate form have been produced. In other cases, the files produced from the linkages are not held in such a way that a record can be retrieved by name or other personal identifier.

List of approved record linkages

A description of all of the approved record linkages will be found in Approved record linkages.