Blood Collection

The more information researchers have, the more questions they can answer about chronic diseases like cancer, heart disease and diabetes. That's why the Study invited selected participants who were between the ages of 30-74 when they completed the OHS questionnaire to also provide a blood sample. By March 31st 2017, the OHS collected over 40,000 Blood samples, which enhance the data already given by participants, and may allow participants to learn something that they did not know about their health.

On this page you will find information about:

What We Do With Your Blood Sample

Participants who provided a blood sample to the OHS had 5 tubes (approximately 35mL or 2.4 tablespoons) of blood taken from a vein in their arm.

Most of each blood sample was frozen so that researchers can use some of it in the future. A portion of the blood was used for immediate analysis. These analyses include:

  • Complete Blood Count: This test analyzes the cells in your blood 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 the results from the immediate blood analysis are shared with participants on their personal home page.

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.