Please note that the Ontario Health Study website and questionnaire will be unavailable due to routine maintenance from 8am on Saturday, April 29th to 8pm Sunday, April 30th.
Because of the overwhelming support of participants like you, we exceeded our target, collecting over 41,000 blood samples!
Leading the fight against cancer and chronic disease
With more than 230,000 participants from across Ontario, the Ontario Health Study (OHS) is one of Canada’s largest long-term health studies. The OHS aims to build a platform for researchers to use now and decades into the future to find ways to better treat and prevent cancer and chronic disease. By collecting health data and information through online questionnaires, physical measures and blood samples, the OHS provides researchers with a rich resource for researchers to investigate the complex interplay between genetics, lifestyle, environment and health.
OHS data and samples in action.
Research projects using OHS data and samples are currently underway!
Tell us how you're doing.
Update us on your health by filling out our first follow-up questionnaire.