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Your research starts here

[Jump to: The OHS Access Process | Data Linkage | Ancillary Studies]

Is your project already approved? Manage your project here.

Health researchers come to the Ontario Health Study when they need longitudinal data on a large adult population, augmented with the availability of blood and other biosamples, genetic data and more. Uniquely suited for investigator-led research, the OHS helps researchers explore their questions about how lifestyle, the environment and genetics interact to affect people’s health.

Take your research idea to reality.

Questions? Contact our Research Operations and Access Officer at

Linkage opportunities


The OHS has a data sharing agreement with ICES that facilitates linking de-identified OHS data with other data holdings at ICES, including, but not limited to:

  • Health services administrative data
  • Census profiles and population estimates
  • Specialized collections such as certain disease registries, and data sets pertaining to First Nations and Métis populations
  • Health survey data
  • Data on certain specific health conditions, including diabetes, high blood pressure, chronic obstructive pulmonary disease (COPD) and heart attacks
  • Clinical data
  • Information on processes and quality of care collected directly from patients’ charts

Learn more about the breadth of ICES data holdings.

Non-ICES researchers, students and knowledge users can access these data through the ICES Data & Analytic Services (ICES DAS). For a full list of ICES Data Repository datasets, including detailed descriptions of individual variables and their values, view the ICES Data Dictionary.

Accessing OHS-linked ICES data requires separate access requests to be submitted to the OHS and ICES. To learn more about how to request OHS data that is linked to ICES data sets, please email

OHS and Ontario Health

OHS de-identified data can be linked with administrative health data at Ontario Health, including the Ontario Cancer Registry.

Accessing OHS-linked Ontario Health data requires separate access requests to both the OHS and Ontario Health. To learn more about how to request OHS data that is linked to Ontario Health data sets, please email


OHS de-identified data can also be linked to local environmental data held by the Canadian Urban Environmental Health Research Consortium (CANUE).

As part of CanPath, some OHS data has been merged with CANUE exposure data sets and are now available to researchers. CANUE has provided researchers with an index measuring exposures to air and noise pollution, green space and more, for every postal code in Canada.

Learn more about CANUE data sets linked to health databases, and review which CANUE data are pre-linked to OHS data.

Ancillary studies

Many OHS participants have consented to being re-contacted about joining other health-related research studies. When appropriate, the OHS has partnered with several independent studies that sought to enable recruitment to their studies, or find matching control groups of participants with appropriate health or demographic profiles.

Contact to learn more about these ancillary studies or discuss your idea with our Research Operations and Access Officer.

Recent partnerships:

The Ontario Sleep Health Study collected accelerometry and sleep respiratory function from approximately 3,300 participants.

The Canadian Alliance for Healthy Hearts and Minds has collected MRIs, and conducted Food Frequency Questionnaires and cognitive assessments from more than 3,000 participants.

A small study out of the University of Toronto (SPARK) asked 60 participants to wear contact lenses to explore new methods for the early detection of breast cancer.