Periods of data collection for Follow-Up 1 (FUP1) assessments were as follows:

FUP1 Tracking: 2014-05 to 2018-12
FUP1 Comprehensive: 2015-07 to 2018-12

Periods of data collection for Follow-up 2 (FUP2) assessments were as follows:

FUP2 Tracking: 2018-06 to 2021-09
FUP2 Comprehensive: 2018-04 to 2021-09

CLSA is working centrally on strategies to link individual level CLSA data with data from health administrative databases across Canada.

In 2021, the Health Data Research Network Canada (HDRN Canada) and the CLSA announced a partnership to enable linkage of the CLSA cohort data with data held at provincial data centres.

As of January 2024, linked CLSA data holdings are available in select provinces. Please visit the Administrative Health Data section for more information.

In general, variables in the CLSA dataset reflect the interview process. In some cases, follow-up questions were only asked if specific answers were given to preceding questions.

Blank values in the Baseline data can represent multiple types of missing data, including:

Valid skip patterns. For example, number of daughters and sons are only asked if the participant answered that they have at least one child. In the CLSA dataset, participants with no children will have blank values for both.

Missing data due to non-completion. There are some participants who skipped entire sections of baseline interview, and therefore have blanks for all the questions in those sections. Indicator variables such as ADM_COMPLETE_MCQ are provided in the documentation accompanying data release and should be consulted when there are large number of missing data to determine if it is due to a participant not completing a section.

In the Follow-up 1 and Follow-up 2 datasets, missing data have been assigned various codes according to the reason the data are missing. Details of the different types of missing data are provided in the data dictionaries accompanying datasets.

Within the CLSA dataset, derived variables (DVs) are variables that are created from other variables. DVs are derived by re-grouping or re-classifying the original variables, to glean information otherwise not available. Some DVs are based on published measures or scales. You will find documentation related to DVs under Researcher Resources.

Participant death is currently captured in three ways: 1) from the next of kin contacting the CLSA directly, 2) through the ‘maintaining contact’ telephone calls that occur between main waves of data collection, or 3) from linkage to provincial vital statistics. Mortality data is now available and includes participant status (vital and withdrawal status), as well as data from the Decendent Questionnaire. For detailed information, see Data Availability.

The CLSA takes great care to check the accuracy and completeness of the data prior to release. However, because of the size of the dataset and the large number of variables, we cannot guarantee the accuracy, completeness, or fitness for any particular purpose of the data. It is the responsibility of each data user to verify their dataset, the accompanying data dictionaries and the data support documentation available under Researcher Resources on our website. If you think your data are incomplete or if you identify errors while conducting your analyses, please contact us at access@clsa-elcv.ca.

The CLSA updates its datasets on a regular basis with additional data, corrections and other updates. Such changes are always indicated by the version number of a dataset. When an update is ready, we send a Data Release Update email to all approved primary applicants, explaining the change(s). You will be able to request the updated dataset if you are approved for those data and you decide that the updates are relevant to your project.

At Baseline, 21,241 participants were enrolled in the Tracking cohort and 30,097 participants in the Comprehensive cohort for a total of 51,338 CLSA participants.

The 30-minute Maintaining Contact Questionnaire (MCQ) interviews with additional health-related questions were completed approximately 18 months after the initial Baseline data collection. A total of 19,052 Tracking participants and 28,789 Comprehensive participants completed the MCQ. The indicator variable ADM_COMPLETE_MCQ is included in the dataset to indicate those participants who completed the MCQ.