Data Availability
Core data and enhancements
About our data
Among the 51,338 CLSA participants recruited at baseline, data are collected from 21,241 participants through telephone interviews. This group is referred to as the Tracking cohort. The remaining 30,097 participants provide data through in-home interviews and Data Collection Site visits. This group is referred to as the Comprehensive cohort.
Core data collection occurs every three years. At each major data collection event, the questionnaires and physical assessments remain largely the same for consistency, but additions to data collection are made to further enhance the CLSA research platform.
Recruitment and baseline data collection were completed in 2015. All participants will be followed-up every three years until 2033 or until death.
Explore the available data
Questionnaire data
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Questionnaire data collected since 2011 through telephone and in-person interviews
Questionnaire data include socio-demographic characteristics, lifestyle and behaviour, physical health, medications, psychological health, cognition, labour force and social health.
To view full questionnaires, visit the Researcher Resources section. A detailed list of questionnaire variables is summarized in the Data Availability Table.
Summary statistics of the questionnaire data are available on the DataPreview Portal.
Physical Assessments
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- Data Availability Table
- Baseline and Follow-up 1: Physical Assessments Summary Table
- Physical Assessments
Physical assessment data collected from the Comprehensive Cohort at Data Collection Sites
Participants in the Comprehensive Cohort visit Data Collection Sites to undergo a variety of physical assessments, including height and weight, blood pressure and cardiovascular measures, bone density, vision, hearing, strength, mobility and cognitive tests.
A detailed list of physical assessments is available in the Physical Assessments Summary Table.
To review Standard Operating Procedures (SOPs) related to physical assessments conducted as part of data collection, visit the Physical Assessments section.
Blood Biomarkers
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Hematology and chemistry reports
Biochemistry biomarker data are available from the Comprehensive Cohort. The hematology and chemistry reports include approximately 30 common biomarkers selected from a curated list of biomarkers relevant to mechanisms related to the aging process and for many diseases of aging.
Subsequent data collection follow-ups will include measurement of the majority of these core biomarkers, creating a unique longitudinal record to facilitate the investigation of a wide range of research questions.
Genomics
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Genome-wide genetic data
The CLSA research platform includes availability and quality assessment of genetic data for 26,622 CLSA participants, comprising genome-wide genotype data for 794,409 markers and whole-genome imputed data for ~308 million genetic variants. Quality assessment includes both marker- and sample-based tests, as well as analysis of population structure and familial relatedness.
Summary of genome-wide genetic data:
- Genotype data for 26,622 CLSA participants with 93% of European ancestry.
- Affymetrix Axiom array genotypes for 794,409 genetic variants, of which 95% are high quality.
- TOPmed imputed genotypes for ~308 million genetic variants.
Epigenetics
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Genome-wide DNA methylation profiling
The CLSA research platform includes genome-wide DNA methylation in peripheral blood mononuclear cells (PBMCs) isolated from selected 1,479 participants using the Illumina Infinium MethylationEPIC BeadChip microarray technology. These high-dimensional, single-assay data are derived from the same group of participants who were selected for genetics, clinical chemistry and metabolomics analyses.
Epigenetics play a significant role in growth, development and disease progression. The epigenome changes in response to diet, stress, and other environmental factors, and these changes can also be passed on from one generation to the next. Investigating DNA methylation as an epigenetic mark will allow researchers to explore how the environment influences cellular function to affect the way that people age as well as the risk of adverse health outcomes.
Metabolomics
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Large-scale metabolomic profiling
Metabolomics is the process of measuring small molecules in blood and tissues, which can help researchers and clinicians identify biomarkers for diseases or health conditions, such as frailty.
Baseline metabolomics data are available from 9,500 participants in the Comprehensive Cohort, including peak area data, batch-normalized imputed data, chemical annotation and sample metadata. The data are derived from the same group of participants who were selected for genetics, clinical chemistry and epigenetics analyses.
Linked Data: Environmental Indicators
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Canadian Urban Environmental Health Research Consortium (CANUE)
The CLSA partnered with the Canadian Urban Environmental Health Research Consortium (CANUE) to link, at the individual level, the CLSA dataset to nationwide data on air quality, greenness, neighborhood factors and weather and climate. The linked data enables research on how environmental factors affect health and aging among people living in Canada.
For additional information on each of these measures, please see the Air Pollution and Meteorological Exposure Measurements Data Support Document and metadata documentation on the CANUE website.
Geographic Indicators
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Census Subdivision and Forward Sortation Areas
Census Subdivision Codes and Names are determined using the Postal Code Conversion File (PCCF) from Statistics Canada. A census subdivision (CSD) is a geographic unit, roughly corresponding to municipalities, whose unique codes can be linked to other sociodemographic or census data.
A forward sortation area (FSA) is a geographic region in which all postal codes start with the same three characters.
Due to the sensitive nature of these geographic indicators, a special request must be made to receive CSDs and FSAs as part of CLSA data requests.
Images and Raw Data
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CIMT, DXA, ECG, retinal scan, spirometry, tonometry and cognition
Images and raw data are available for the following measures: CIMT, DXA, ECG, retinal scan, spirometry, tonometry and cognition. For more information on the types of data available, consult the Data Availability Table.
Please note that the request for images and raw data usually incurs additional costs beyond the current data access fee, and these are outlined on the Data Access section of our website. Requests for images and raw data may prolong the processing time of applications, and it may take longer to receive these data than the six months to receive alphanumeric data.
COVID-19 Questionnaire Study Data
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COVID-19 Questionnaire data from 28,565 participants
The CLSA COVID-19 Questionnaire Study collected longitudinal data from April 2020 to December 2020. The baseline and final exit questionnaire captured information on COVID-19 symptoms and status, risk factors, healthcare use, health behaviours, psychosocial and economic consequences of the pandemic. The weekly, biweekly, and monthly questionnaires focused on symptoms, COVID status, and behaviours.
COVID-19 Seroprevalence Study Data
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COVID-19 seroprevalence and questionnaire data from 19,334 participants
The CLSA COVID-19 Seroprevalence Study collected blood samples and questionnaire data from October 2020 to July 2021 with an overall objective to estimate age and sex specific prevalence of antibodies to SARS-CoV-2 in older adults by all provinces. The questionnaire captured information about COVID-19 status, COVID-19 symptoms, housing, risk factors, risk acquisitions, and health behaviours related to the virus. Participants either provided a venous blood sample at a CLSA Data Collection Site or a dried blood spot sample using a home collection kit.
Mortality Data
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Participant status and decedent questionnaire data
The CLSA research platform includes information on vital status and withdrawal status of participants.
Additional mortality data are collected through a short decedent questionnaire, including details surrounding death, caregiving, participant health-care preferences and decisions, and quality of death and dying.
Interested in accessing administrative health data?
Researchers can apply to access linked CLSA cohort data at select provincial data centres. Applications for multiregional data must be submitted through Health Data Research Network (HDRN) Canada’s Data Access Support Hub (DASH).
COVID-19 Research
Pandemic impacts on older adults
The CLSA research platform includes questionnaire, seroprevalence and imaging data examining the immediate and long-term impacts of both the pandemic and the virus that causes COVID-19.
Brain Health Research
Understanding cognitive aging
Enhancements to the CLSA research platform have included brain imaging, microbiome analyses and additional cognitive tests to help understand healthy brain aging and markers of cognitive decline.
Data Access
The CLSA data are currently available to approved public sector researchers in Canada and elsewhere. Learn more about eligibility and how to apply for access.
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