KAROLY ARVAI
Ontario researchers have launched the most ambitious collection of health data ever attempted in North America: it will involve millions of people and track them for the rest of their lives.
The goal of the Ontario Health Study, which has the backing of government-financed organizations, is to compile information on medical histories, lifestyle habits and other data from people representing the province's demographic makeup and provide it to researchers for study.
If the organizers get enough people, the project could make Canada a global leader in the compilation of health information for research. Such a vast database on millions of individuals spanning several decades will allow researchers from around the world to conduct thousands of studies on everything from common chronic conditions such as cancer or heart disease to rare diseases.
Organizers say that researchers would be able to use the information to study such things as whether proximity to green space contributes to heart disease risk, whether some jobs increase the chances of developing cancer, or how neighbourhood, diet, background and other factors influence people's health.
"It's a game changer," Lyle Palmer, executive scientific director of the Ontario Health Study, said of Wednesday's announcement. "It would change how we do clinical medicine, it would change how we do research, it would change how we turn research into clinical practice."
One of the major challenges to important medical breakthroughs is the fact that the sample sizes in most traditional research studies often are too small to indicate subtle trends or characteristics shared by people who develop serious diseases or health problems. Even medical studies that involve thousands of people and span numerous years can miss important clues.
Ontario has 9.5 million eligible people - the subjects must be 18 or older- and the researchers are aiming to get as many of them as possible in the voluntary study, which organizers have been working on for two years.
The sheer size and scope of that means researchers will have an almost unprecedented ability to identify common threads among people who develop certain diseases, the type of commonalities that are so subtle they can be found only by looking at the largest cross-section of society for the longest period.
"We know the diseases we're working with are very, very complicated. To really unpack complex pathways, we need everyone to take part, basically," said Dr. Palmer, who came to Canada from Australia to lead the health study. "We need millions of people, not thousands of people."
This type of population-based research follows in the footsteps of some of the most important medical research ever conducted. The Framingham Heart Study in the United States, which began in 1948 to follow more than 5,000 people and continues today, led to the discovery in 1960 that cigarette smoking is linked to an increased risk of heart disease. In 1970, Framingham researchers found that high blood pressure leads to an increased risk of stroke.
Observers say the Ontario Health Study data could lead to important medical discoveries.
"It's very important," said David Henry, president and CEO of Toronto's Institute for Clinical Evaluative Sciences. "What it will do is spawn or nest hundreds and hundreds of studies."
Those who sign up for the study will have to answer questions about their medical history, lifestyle habits and family medical history. Since the data will be collected online, the study will still be able to follow people who move away from the province.
Researchers also plan to go back to participants on occasion and ask additional questions, such as how conducive their neighbourhoods are to walking, to build a "rich database," Dr. Palmer said.
In addition, 100,000 of those who sign up for the study will be asked to come to Toronto for a thorough physical assessment.
But the success of the study will hinge on its ability to recruit participants that represent Ontario's diverse population, said Michael Farkouh, director of clinical trials at University Health Network's Peter Munk Cardiac Centre. But there's a risk certain groups, such as highly-educated individuals or those from one ethnic background, will dominate the overall number of participants and end up skewing research results, a phenomenon known as "self-selection bias."
The best way to avoid that is to have high participation rates, Dr. Farkouh said.
The Ontario Health Study has plans to roll out a massive public awareness campaign that will use public transit advertisements, online ads, notices in doctor's offices and social media to encourage people to enroll. The organizers are targeting ethnic groups with publicity in different languages.
Such data-collection projects are expensive. The study has a budget of about $8-million a year, Dr. Palmer said, and the majority of funding will be provided by the Ontario Institute for Cancer Research, Cancer Care Ontario, the Ontario Agency for Health Protection and Promotion and the Canadian Partnership Against Cancer.
Only a handful of Ontario Health Study staff will have access to personal information of study participants, Dr. Palmer said. Researchers will receive data without personal details. The study will also use sophisticated access systems that keep all information password-protected and encrypted.
Carly Weeks