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.

Clicking on the variable name, in the variable view reveals more detailed information about that variable. (This function is not available for all study variables). This information includes the question pertinent to the variable, the variable label, a list of the response option categories and some automatically generated summary statistics. In some instances, additional notes on skip patterns or references are included as well.

In the variable view, clicking on the name of each variable reveals information that is more detailed. For example, under Categories, the variable information page will include the following information:

Name: the value entered for a response in the questionnaire;

Label: the response (or response category) corresponding to each value (Name);

Missing: values corresponding to a question not answered, (don’t know or not applicable, refused).

Multiple-choice questions are represented by either a single variable or multiple variables, depending on what the question allows:

– A question allowing only one response is represented by a single variable that can take on multiple values. Open-text responses are permitted in many questions; common and distinct responses are recoded to create new categories within the variable itself.

– For a question allowing multiple responses, each possible response category is assigned its own binary variable. Open-text responses are also permitted in many of these questions; common and distinct options are also recoded to create additional variables within the question scope. The number of variables corresponding to that question matches the number of response options.

To obtain all the variables contained in a questionnaire, type the two or three letter prefix (e.g. SDC for Socio-demographic Variables) into the full-text search box in the Variables listing, under “Variable properties > Name”. You can also use more general terms such as ‘food’, ‘work’, etc. (under “Variable properties > Label”) to find variables related to those terms, however, search terms are not exhaustive. For more information on the variables included in a questionnaire, please visit  Researcher Resources.

Final drafts of all manuscripts, reports, reviews, pre-prints and other proposed primary publications describing research using CLSA data and/or biospecimens must be sent to the CLSA, by the primary applicant, for review at least 15 working days prior to the anticipated submission. Abstracts, posters and presentations do not need to be submitted for review but should include appropriate acknowledgements. Please review our Publication and Promotion Policy for CLSA Data Users for additional information.

Researchers are invited to submit data access requests using Magnolia, the CLSA’s online data access application system. Requests to access the CLSA data are reviewed by the Data and Sample Access Committee (DSAC). Please consult Researcher Resources, which includes the Data and Sample Access Policy and Guiding Principles, the CLSA protocol(s), the CLSA Data Collection tools and resources, and the information on the data access application process before preparing an application.