Lab Canada

Research project becomes largest single health study in Canadian history

Toronto, ON – The Ontario Health Study (OHS), an ambitious research effort designed to help scientists understand the complex factors behind many common diseases, says that more than 175,000 Ontarians have now joined the study. It says the milestone makes it the largest single health study in Canadian history.

“The Ontario Health Study is being watched around the globe because of the novelty of its online approach, the significance of its large scale and the diversity of participants,” said Professor Lyle Palmer, the study’s executive scientific director. “We will be following individuals over their entire lifespan, giving us the ability to look at the development and progression of common conditions in the general population.”

Every Ontario adult aged 18 and over can enroll in the OHS and complete an online health questionnaire at The questionnaire, which takes 30 to 40 minutes to complete, asks participants to provide information about health-related subjects such as personal and family medical history, where they live, and their lifestyle and diet.

All information provided to the OHS by participants is protected by embedded privacy tools built into the core of the study’s technology, delivering the maximum degree of privacy and ensuring that personal data is “de-identified” and automatically protected. When participants sign up for the study and complete the online questionnaire, all identifying information, such as their name and address, is separated from the health information provided.

“It is important that we continue to recruit participants from all regions of the province as lifestyle, diet, culture, ethnicity and environmental factors vary greatly from region to region,” said Dr Palmer. “This range and diversity is a defining difference in our work and one of the key factors that drew me to the opportunity.”

Dr Palmer came to Canada in 2010 to lead the studt, leaving his post as the founding Winthrop Chair in Genetic Epidemiology and the founding director of the Centre for Genetic Epidemiology & Biostatistics at the University of Western Australia, where he was also a professor in the Schools of Medicine & Pharmacology and Population Health.

More than 320 senior scientists and clinicians at universities, hospitals and research institutes across the province oversee the study, collaborating on its development and the design of the online health questionnaire. They will also work in partnership on future follow-up questionnaires as the study follows participants’ health over the coming decades.

The next phase of the study is set to roll out this spring.