Blood Collection

Please note that Study recruitment and our Blood Collection Program will be ending on March 31st, 2017. Click here to learn more.

The more information researchers have, the more questions they can answer about chronic diseases like cancer, heart disease and diabetes. That's why we're inviting selected participants who were between the ages of 30-74 when they completed the OHS questionnaire to also provide a blood sample. Participation will enhance the data you've already given and may allow you to learn something that you did not know about your health.

On this page you will find information about:

Providing a Blood Sample

Providing a blood sample to the OHS (or not providing one) is completely up to you. You're still an important part of the Study even if you choose to only fill out the questionnaire. And remember that if you do provide a sample the information collected is for research purposes only – it is not diagnostic and does not replace a visit to your doctor or a healthcare professional.

If you've completed the baseline questionnaire you can log on to your account to complete the next steps towards providing a blood sample. You will be asked to complete a short questionnaire to ensure that you are eligible. If you registered for the Study before June 2014, you will also need to fill out a consent form. Once you've completed these steps your personalized requisition form will be available.

You will need to print and bring the requisition form to provide your sample. If you do not have access to a printer, please write down the LID number and verification code (on the top left of the form) and bring them with you to your appointment.

There are two ways to provide a blood sample:


The Ontario Health Study has a partnership with LifeLabs to collect blood samples for the Study. LifeLabs is a Canadian company that handles more than 100 million laboratory test annually. They have clinics in communities across the province. To find out how to book an appointment, click here.

Local Study Centres

The Study travels to communities across Ontario, hosting mobile blood collection clinics. To find out if the OHS is visiting your community, click here.


You are eligible if:

  • you were between the ages of 30-74 when you completed the OHS questionnaire; and
  • you have not already provided a blood sample to the OHS.

For your safety you currently are NOT eligible if:

  • you have a blood-clotting disease such as hemophilia;
  • you have received a blood transfusion in the past 2 days;
  • you have had any procedures performed on both sides of your body that would make you unable to give a blood sample (e.g., lymph nodes removed from your arm or chest, an arteriovenous (A-V) shunt for haemodialysis, etc.); and/or
  • you have observed any condition that makes sample collection impossible (e.g., rashes, oedema, open sores, wounds, cast, occluded veins on both arms, etc.).

What We Do With Your Blood Sample

If you decide to provide a blood sample, 5 tubes (approximately 35mL or 2.4 tablespoons) of blood will be taken from a vein in your arm.

Most of your blood sample will be frozen so that researchers can use some of it in the future. Some of your blood will be used for immediate blood analysis. These analyses include:

  • Complete Blood Count: The cells in your blood will be analyzed to look for anemia, infection and other diseases. This test gives a general indication of your health.
  • Glycosylated Hemoglobin Analysis: This test measures the long-term level of sugar in your blood, and is used to detect and monitor cases of diabetes. This test will help health researchers study diabetes, heart disease and obesity.

Some of your results from the immediate blood analysis will be shared with you. These will be available on your personal home page after your blood had been analyzed. Generally, it takes around 10 days for this information to be posted to your home page. When the results are available, you will receive an email to notify you of this.

Building a "biobank": Find out more about how the OHS stores your sample for future research.

Protecting Your Privacy

We know how important it is to keep information about your health private and confidential. When samples are processed and stored for future research, anything that personally identifies you, such as your name, will be removed and replaced with a unique code. This unique code will let us link the sample you have provided while allowing us to keep your identity confidential. Only a handful of staff at the Ontario Health Study have access to the electronic key that matches your unique code to your identity.

Your coded information is encrypted, or "scrambled," before it is transferred to our data centre. Coded information is only transferred over secure connections similar to those used for online banking. These secure connections are very difficult for outsiders to breach. The coded information is then stored on encrypted servers (very large computers) in a locked room that very few people can access. We only unscramble the information after it has safely arrived on our servers. The information you provide will be stored on a separate server from your questionnaire responses or anything that personally identifies you (e.g., name, address, OHIP number).

Access to Data

All test results are de-identified and stored on secure servers at the Ontario Health Study. Access to the data and samples is governed by strict guidelines that protect the confidentiality of participants:

  • All health researchers using data from the Study must receive approval from a Research Ethics Board or similar committee before access is given.
  • No information about you will be given to your employer, family members or commercial entities such as insurance companies.
  • Samples are processed at repositories located in Canada. All samples will be given a unique code and no personal information will be kept on tubes that store blood samples.