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Frequently Asked Questions

About the Ontario Health Study

What sets the Ontario Health Study apart from other studies is the opportunity to follow the health of so many diverse people. The Study may detect new risk factors, or combinations of risk factors, and may be able to investigate many less common diseases. The ethnic and geographic diversity in Ontario also makes the province ideal to investigate a variety of risk factors for common diseases across different ethnic groups and environments. The Study is one of the first studies to collect data relevant to many diseases from a large-enough number of people to draw meaningful conclusions. The Ontario Health Study is part of the Canadian Partnership for Tomorrow’s Health, a landmark study whose goal is to recruit and follow the health of 330,000 Canadians in seven regions across the country.

Also making the Ontario Health Study unique is that it takes advantage of the many research resources existing in Ontario, including world-leading medical research in many areas. For example, when you give us your permission to link to your administrative data, we are able to link to many valuable sources of information that are unique to Ontario, such as the Ontario Cancer Registry. Some of the best-linked health data in the world – collected for routine administrative purposes – exists in Ontario.

Diseases such as cancer, heart disease and diabetes are the primary causes of death in Canadian adults and treating these and other illnesses costs the Canadian health care system billions of dollars annually. Additionally, we are starting to see the onset of diseases in younger populations. The Ontario Health Study will try to discover which factors increase the risk of developing various diseases, as well as what can be done to reduce the chance of developing them. These risk factors may include where people live and work, what they eat, how much they exercise, whether they smoke and other factors that have not yet been identified.

Findings from other long-term studies have already helped improve health care for all of us. This is your chance to help make a difference to the health of future generations. Also, by participating in the Ontario Health Study, you will be part of a broader, pan-Canadian initiative as the OHS is part of the Canadian Partnership for Tomorrow’s Health (CanPath). To learn more, visit canpath.ca.

Though our primary method of staying in touch with you will be through email, we may also contact you via regular mail or phone. As technology changes over time, we may use additional ways to contact you as well.

Some results from the Ontario Health Study will be available within a few years. Other findings will come from following participants over a long period of time.

The best way to conduct this type of research is to collect health information over long periods of time so that the development of disease can be tracked through time.

The OHS is funded by four agencies and government partners whose goals include conducting research to improve care and reduce the number of people who are diagnosed with common diseases. The goal of the Ontario Health Study is to investigate what causes diseases and to improve strategies for the prevention and treatment of these diseases.

No. The Ontario Health Study is a not-for-profit health research platform begun in 2009, when the OHS began to recruit more than 225,000 Ontario adults to complete health-related online questionnaires to follow their health over time. The OHS is part of the Ontario Institute for Cancer Research located in Toronto.

Taking Part

The Ontario Health Study will continue for a long time, and one of the goals of the Study is to collect information about your health throughout your lifespan. You will be contacted again in the future to complete additional questionnaires, and may be asked to provide additional samples and measurements. Each time you are invited to participate in a new part of the Ontario Health Study, you will receive a series of reminders to complete that activity. These reminders will provide you with an opportunity to learn more about what you are being asked to take part in, and to ask any questions you might have. The Study will also send you updates about the progress the Ontario Health Study is making, and information about new initiatives the Study is planning. You can always choose not to receive these updates, and providing additional information, measurements or samples to the Study is voluntary.

The Ontario Health Study’s Blood Collection initiatives concluded on March 31st, 2017. In the future, existing participants may be invited to participate in a second round of blood collection.

Registration of new participants ended March 31st, 2017.

Online Questionnaires

If you agreed to be contacted for occasional follow up, we will invite you to participate in subsequent questionnaires where you will be asked for updated information about your health and your environment. We cannot update previous questionnaire responses because integrating new information from some (but not all) OHS participants at different time points would greatly complicate the data structure for our questionnaires.   

Data analyses rely on a complex statistical framework. One common type of analysis that researchers employ in studies like the OHS is ‘time-to-event data’ in which participants are followed from a clearly defined starting point in time until they experience the researcher’s ‘event of interest’ (such as a cancer diagnosis). It is not always possible to follow all participants until that health event occurs, so researchers will define the ‘end date’ as either the date of the disease diagnosis, the date of last follow-up (either as the most recent OHS follow-up questionnaire or through data linkage), or the date when the participant drops out of the study or passes away.

If you consented to data linkage, approved researchers are also able to access updated information about many end points of interest through other health care data sets held elsewhere (such as the Ontario Cancer Registry).

Here are the types of questions asked in the COVID-19 Questionnaire:

  • Your health conditions and risk factors for COVID-19
  • The impact the pandemic has had on your mental, emotional, social and financial wellbeing, what kind of support network you have around you, and how your job status may have been affected
  • Whether you were tested for COVID-19 or suspected you had an undiagnosed case of COVID-19
  • Which symptoms you may have experienced
  • If you were hospitalized or received medical care
  • The potential source of your exposure (recent international travel; household community or healthcare contact with a known case; or unknown)

If you are already a Study participant, we will contact you to let you know when a new questionnaire is available for you to complete.

Yes. Even though you have moved, you are still eligible to complete any future follow-up questionnaires.

There have been five Ontario Health Study questionnaires:

  • The Baseline Questionnaire (September 2010-March 2017)
  • The Follow-Up Questionnaire (November 2016-March 2018)
  • The Work History Questionnaire (April-December 2019)
  • The COVID-19 Questionnaire (May-November 2020)
  • The COVID-19 Antibody Questionnaire, sent to selected participants who completed the COVID-19 Questionnaire (March, 2021- June 2022)

As a Study participant, you will be contacted again in the future to complete additional questionnaires, and may be asked to provide additional samples and measurements. The Ontario Health Study will continue for a long time, and one of the goals of the Study is to collect information about your health throughout your lifespan.

Some of the topics we expect to cover in follow-up questionnaires include mental health, diet and physical activity, stress levels, information about your work environment and lifestyle, and the walkability of your neighbourhood.

Once you have consented to participate in the Ontario Health Study, the information that you have provided will be retained unless you withdraw from the Study. Researchers may still find the information you did provide useful for their work.

If you experience technical difficulties while completing a questionnaire, please contact our call centre at 1-866-606-0686 or send an email to info@OntarioHealthStudy.ca. Our call centre is open Monday to Friday from 9 a.m. to 5 p.m.

You spend a lot of time at work and work has a big impact on you, whether it affects you mentally, physically or emotionally. Your job is relevant to your health and helps researchers make connections on how it impacts your health. The information from the Work History Questionnaire will be added to the data we’ve already collected through previous questionnaires regarding your health & lifestyle. This will create an even richer resource for research into the causes of cancer and other chronic diseases.

Here’s the types of questions asked in the Work History questionnaire:

  • All the jobs you’ve held, whether you’re currently employed, between jobs, or retired
  • Working conditions; how physical was the work?
  • The demands of the job, and the level of control you have over how much work you are given
  • How a job impacted your mental, social and emotional well-being
  • How satisfying the work was, and whether you felt supported in your role
  • Exposures to chemicals or hazards on the job, and your use of protective equipment
  • Your commute; how you got to work, and how long it took

No. However you will receive a follow-up questionnaire asking for an update of your health and you can provide the correct response(s) at that time.

We contact our participants every couple of years to obtain updated health and lifestyle information using follow-up questionnaires, which are designed to be snapshots of participants’ health over a long period of time. If you gave us your permission to link to your administrative health data, changes will also be captured via administrative and medical databases such as OHIP and the Ontario Cancer Registry.

Login issues

If you have forgotten both your username and password, you must recover your username first.

To recover your username, please follow the steps below:

  1. Go to the log-in page on the OHS website by clicking here;
  2. Click on the blue text that says “Forgot your username?”;
  3. Enter the email address you used to register for the Study;
  4. Click on “Send me my Username”;
  5. Your username will be sent to you via email.

If you are unable to recover your username using the “Forgot your username?” button on the log-in page, please contact the OHS at 1-866-606-0686 or info@ontariohealthstudy.ca for assistance.   Our call centre is open Monday to Friday from 9 a.m. to 5 p.m.

If you have forgotten both your username and password, you must recover your username first.   

To reset your password, please follow the steps below:

A. Password reset via email:

  1. Go to the log-in page on the OHS website by clicking here;
  2. Enter your username, and then click on the blue text that says “Forgot your password?”;
  3. A window will appear asking you to choose the method for resetting your password. Choose the first option, “Click here to reset your password via email”;
  4. Enter your username or the email associated with your OHS account and click “Send me my password reset email”;
  5. Open the email sent to your email inbox and click on the link to reset your password. Please note that the link is only active for 12 hours;
  6. Create a new password that is 14 to 25 characters long, and includes at least three of the following:
    • Uppercase letter
    • Lowercase letter
    • Number (0-9)
    • Special character (!@#$%^&*…);
  7. Once you have confirmed your new password, click on “Apply”. You will now be sent back to the log-in page. Please enter your username and new password to log in.

B. Password reset through security questions:

  1. Go to the log-in page on the OHS website by clicking here;
  2. Enter your username, and then click on the blue text that says “Forgot your password?”;
  3. A window will appear asking you to choose the method for resetting your password. Choose the second option, “Click here to reset your password using security questions”;
  4. Enter the letters you see in the spam guard (please note that these are not case sensitive and there are no spaces) and then select “Enter”;
  5. Complete the security question(s) and click on “OK”;
  6. Create a new password that is 14 to 25 characters long, and includes at least three of the following:
    • Uppercase letter
    • Lowercase letter
    • Number (0-9)
    • Special character (!@#$%^&*…);
  7. Once you have confirmed your new password, click on “Apply”. You will now be sent back to the log-in page. Please enter your username and new password to log in.

Privacy & Confidentiality

Participants who joined the Ontario Health Study have given their informed consent to sharing their health information for uses approved by a Research Ethics Board and a data access committee. The OHS collects and uses participants’ personal identifiers (such as name, email, mailing address, health card number, and birth date) so that the Study can:

  • Stay in touch with participants through occasional emails or study updates shared in OHS newsletters
  • Invite them to additional Study activities such as health questionnaires or blood collection
  • Facilitate greater research opportunities by linking their information to environmental databases such as CANUE.

With participants’ consent, the Study also collects personal identifiers to link their data with other sources of data, notably administrative health data (such as data from the Ontario Cancer Registry). The OHS never shares personal identifiers with researchers.

The security and confidentiality of your personal health information is very important to us. We have put in place strict security measures, which include sophisticated computer controls and highly secure access systems. The main methods we use to protect your confidentiality are:

  1. Your information is stored with all identifying information removed (“de-identified”) – this means any information that can identify you, such as your name and address, date of birth or health card number is removed from your data and stored separately.
  2. All Information is password-protected and encrypted. The computers that hold your information are protected by the same kind of encryption technology that is used by banks to protect their customers’ online banking transactions.
  3. Access is kept to a minimum. The OHS restricts who can access your health information. Only a small number of staff members who have signed confidentiality agreements have access to the information you have shared with the Study, and they only access it for necessary operational purposes.

Once you have completed a questionnaire, your responses are de-identified (de-linked from your name, address, email or other personal information) and are exported to another secure database for research and reporting purposes. All physical systems are hosted at a secure data centre in the Ontario Institute for Cancer Research. Due to the importance of the information collected by the OHS, we make back-up copies of the information in our databases on a regular basis. Certain third-party organizations have been hired by the OHS to store these copies or to transport Study information, but this information is encrypted and they cannot see or use it.

All the information you provide is encrypted to ensure that your data remains confidential. This protection exists at all points between your web browser and the database where your data is stored. Furthermore, identifiable information such as your name is placed in an isolated database separate from your questionnaire responses.

Ontario Health Study/Ontario Institute for Cancer Research (OICR) staff: A limited number of staff members from the Ontario Health Study and the OICR IT department will have access to your personal information.

Researchers: The Ontario Health Study receives requests from researchers around the world to access the Study’s data and samples. All requests must pass a strict scientific and ethical review and receive approval before any data or samples will be shared with a researcher. The data and samples collected from you will only be disclosed to researchers once all information that directly identifies you has been removed. Researchers who are given access to Ontario Health Study data or samples must sign a Data Access Agreement to ensure that no attempt is made to re-identify participants, and they must provide a Certificate of Destruction for that data once the project has concluded.

Researchers who have received approval for a research study may wish to collect information from you that has not been collected as part of the Ontario Health Study. If this occurs, you will be contacted by the Ontario Health Study regarding the request. You have the option to participate in the research study or to refuse. A list of approved studies is maintained on the OHS website.

Research Ethics Board: The Research Ethics Board has the right to review Study data in order to ensure that the Ontario Health Study is following proper procedures.

Custodians of administrative health data: Over 89% of OHS participants consented to having their questionnaire responses and analyses of their samples linked to administrative data. This includes databases like the Ontario Cancer Registry and OHIP claims database. To complete this linkage, personal identifiers have been shared with Ontario Health (Cancer Care Ontario) and ICES. OHS participant identifiers are securely stored by Ontario Health (CCO) and ICES to allow OHS data to be linked to multiple databases held at these institutions. (See how researchers access Ontario Health (CCO) administrative data). When OHS participants ask to withdraw from the Study and revoke their permission for the OHS to use their data for future research, the OHS ensures this withdrawal request is communicated to both Ontario Health (CCO) and ICES, as appropriate.

You do not have to provide your health card number in order to participate in the Ontario Health Study. However, we ask you to give it to us so we can link the information you provide to the OHS to your routinely collected administrative/medical data and your health records. For example, every time you undergo certain tests (e.g., a mammogram), the fact that you had this test is noted and stored in a database. This is referred to as “administrative data.” By linking the information you provide to the OHS with administrative data, researchers are able to ask a broader range of questions, such as whether screening programs are effective and whether there are “hot spots” across the province where a certain disease is more common.

Since data linkage involves linking information about the same person from multiple sources, it is important to make sure that the information being linked is about the same person. Your health card number is unique to you and is the perfect means to link information. Very strict privacy practices are in place when information from multiple sources is linked together. Researchers must document how they will ensure the confidentiality of your information and must receive approval from a Research Ethics Board and an ethics committee before they can access your health information.

Researchers using OHS data must go through strict protocols to request linked data from Ontario Health (Cancer Care Ontario). Once their research is complete, they must provide to the OHS a certificate of destruction to show they have destroyed their data sets. For its part, Ontario Health (CCO) securely stores the OHS participant identifiers separately on a secure server.

See how researchers access Ontario Health (CCO) administrative data. When OHS participants asked to withdraw from the Study and revoke permission for the OHS to use their data for future research, the OHS also ensures that data (from withdrawn participants) are no longer available to Ontario Health (CCO).

The Ontario Health Study was granted approval by the Research Ethics Board at the University of Toronto. This approval is reviewed and approved annually. The Research Ethics Board approves all aspects of the research study and ensures that it meets the required ethical criteria.

International researchers must receive ethical approval from the organizations they work for prior to obtaining any Ontario Health Study data. All proposals will be reviewed by an Access Committee and researchers must sign a Data and Biosamples Access Agreement before they are given access to Ontario Health Study data.

The information you have provided to the Study will still be valuable and will continue to be used for approved research purposes. When an OHS participant passes away, the OHS learns about this via data linkage with the Government of Ontario’s Registered Person Data Base (RPDB). This linkage with the RPDB helps keep our OHS database accurate so that we no longer attempt to contact the deceased participant, and means we no longer rely on a participant’s family to notify us of the participant’s death.

The results of the Study will be available to everyone, including the government, but no participants will ever be identified in any publication, presentation or report.

Your information is being collected for research purposes, and will not be accessible to the police, law enforcement officials or lawyers unless there is a requirement to do so by law (e.g., in very rare situations, a warrant could be issued by a court of law). This is largely hypothetical as we are not aware of any instance of the courts requesting information collected for health research purposes. If we were ever required to provide authorities with your information, we would inform you of the legal investigation if possible.

No personal information will be given to insurance companies or employers.

2-Step Verification at Account Log-In

To better protect your account, you may periodically be asked to enter a one-time code sent by email, a process called 2-Step Verification which provides an additional layer of security to help ensure that you – and only you – can access your account.

First, we recommend checking the “spam” or “junk” folders of your email inbox to see if your verification code email landed there. If it did, mark that email as “not spam/junk” so future verification code emails will land in your main inbox.

If the verification code email is not in your spam/junk folder, refresh your email inbox page by either clicking the “Refresh” button or reloading the web page in your browser. There may be a brief delay before the verification code email reaches your inbox.

If it has been several minutes and you still don’t see the verification code email, you can request a new code by clicking on the “Request New Code” button on the verification code entry screen and a new code will be sent.
If you still haven’t received a verification code email, please contact the OHS Call Centre at 1-866-606-0686 or info@ontariohealthstudy.ca for assistance.

Please re-check the verification code in the email you received, and re-enter it carefully. You may also copy and paste this code.

If you requested a new code because you didn’t receive the first verification code email, double check that you are referring to the most recent email.

If you are still experiencing issues entering your code, please contact the OHS Call Centre at 1-866-606-0686 or info@ontariohealthstudy.ca for assistance.

Each verification code expires after 15 minutes. Once your verification code has expired, you will be redirected to the main sign-in page. You can then re-enter your username and password to receive a new verification code via email.

To protect your information, your OHS account will be temporarily locked following five unsuccessful code entries. Your account will automatically unlock in 30 minutes.

If you require assistance, please contact the OHS Call Centre at 1-866-606-0686 or info@ontariohealthstudy.ca and we will be happy to help you.

No, only when we need to verify your identity.

As this additional layer of verification is necessary to ensure the information you provide is kept secure, participants are not able to opt out of 2-Step Verification. Your information is incredibly valuable to the researchers who use your data, so we do everything we can to keep our systems secure.

For future enhancements to the verification process we may expand to the use of text messages (SMS) or authenticator apps, but currently verification codes will only be sent to the email address associated with your account.

We’re here to help! Please contact the OHS Call Centre at 1-866-606-0686 or info@ontariohealthstudy.ca for assistance.

Consent & Withdrawal

The success of the Ontario Health Study depends upon the ability to follow participants over many years. The value of your information will be greatly reduced if you withdraw from the Ontario Health Study. However, you are able to withdraw from the Study at any time. If you decide you no longer want to participate, we will not contact you for any additional information. To withdraw from the Study, please log in to your OHS account and click on “Study Preferences” in the blue banner. Next click the “Withdrawal Options” box. You will be asked to indicate what you would like the OHS to do with the information and samples you have already provided to the Study. You can choose from one of the following three options:

  1. No further contact: the Ontario Health Study will no longer contact you or ask you to participate in ongoing Study activities, but will continue to have your permission to keep and use information and samples you have already provided, and to continue to access information in administrative or medical databases (e.g., the Ontario Cancer Registry) and your personal medical records if you consented to this at the time you enrolled.
  2. No further access: the Ontario Health Study will no longer contact you or ask you to participate in ongoing Study activities, and will not collect any further information about you from administrative and medical databases (e.g., the Ontario Cancer Registry) or your personal medical records, but will still have permission to keep and use information and samples you have already provided.
  3. No further use: the Ontario Health Study will no longer contact you or ask you to participate in ongoing Study activities, collect additional information about you, and any information or samples you have already provided will be removed from our databases. It is not possible to remove information or samples that have already been provided to researchers for analyses. Your signed consent and withdrawal will be kept as a record of your wishes.

Should you have any questions or if you would like more information about your withdrawal options, please telephone the call centre at 1-866-606-0686, Monday to Friday, from 9 a.m. to 5 p.m., or send an email to info@ontariohealthstudy.ca.

Your consent will remain valid unless you withdraw from the Study. The information and samples you provide will be kept as long as they are valuable for health research. Should this occur, a decision will be made about what to do with your information and any remaining samples.

Technical Issues

As a security precaution, our website will lock your account for 30 minutes if the incorrect username and/or password are submitted three times in a row. To regain access more quickly we recommend resetting your password, which will immediately unlock the account and allow you to log in. Password reset instructions are available here. If the problem persists, please contact the Ontario Health Study call centre at 1-866-606-0686, Monday to Friday from 9 a.m. to 5 p.m. for assistance.

It is possible that you have missed answering a question on the page or entered an unacceptable value for a question. Please make sure you have not entered any extra spaces in open text fields as this is a common source of error messages. Please scroll to the top of the screen to check for any error messages that may appear. Error messages will appear just above the question that has caused the error.

The system will save all of the questionnaire answers you have provided up to this point (up to the last completed page). Please log in again to resume answering the questionnaire where you left off. If you cannot log in again, please contact our call centre at 1-866-606-0686 or send us an email at info@OntarioHealthStudy.ca for further assistance. Our call centre is open Monday to Friday from 9 a.m. to 5 p.m.

The speed at which the questionnaire moves from screen to screen could be affected by a few things, including the number of people online at the same time, the speed of your internet connection or the speed and configuration of your computer. To help improve the speed of the questionnaire, please close all other programs on your computer and do not download other files, programs or updates while you are completing the questionnaire. If the problem persists and you are not able to complete the questionnaire, please contact our call centre at 1-866-606-0686 or send us an email at info@OntarioHealthStudy.ca for further assistance. Please note that our call centre will not be able to diagnose or fix any technical issues with your actual computer. Our call centre can only answer questions related to the Study and is not an IT Help Desk. Our call centre is open Monday to Friday from 9 a.m. to 5 p.m.

The system will save all of the questionnaire answers you have provided up to this point (up to the last completed page). You may exit the questionnaire and log in again to resume where you left off. If you cannot log in to the questionnaire again, please contact our call centre at 1-866-606-0686 or send us an email at info@OntarioHealthStudy.ca for further assistance. Our call centre is open Monday to Friday from 9 a.m. to 5 p.m.

Please double check the response you are trying to enter. The questionnaire has been designed to allow responses that fit within certain categories. For many responses, this means that values entered have to be between certain ranges and values that are outside these ranges will create an error. For example, you cannot enter that you were diagnosed with a certain condition at age 65 when you are only 30. By designing the questionnaire in this way, we can ensure we are getting the most accurate data. If you continue to experience difficulty, please contact our call centre at 1-866-606-0686 or send us an email at info@OntarioHealthStudy.ca. Our call centre is open Monday to Friday from 9 a.m. to 5 p.m.

If you have already tried signing into your account using the correct username and are still having problems accessing it, unfortunately, you will need to change your password.

If you’ve updated your email address, your username won’t automatically change to match. Email info@ontarihealthtudy.ca and we’d be happy to change your username to match your updated email address.

  • You may have made an error when typing your new password, OR your Caps Lock may be on
  • You may have entered an incorrect username
  • If you use a password manager tool, your computer may only have saved your old password. If this is the case, please delete the saved password and manually re-enter the new password in the password field.

Please check your junk and/or spam folders of your email. You can also try to reset your password by answering the security questions.