At the Offord Centre we take privacy very seriously and have a number of measures in place to protect the data we receive.


The EDI uses passive consent

Like many other population-based measures, the EDI uses passive (or implied) consent (in all provinces except for Alberta). Passive consent means that after providing parents with information on the EDI, in the form of parent letters sent home from school, we assume parents are willing to participate unless we are told otherwise. Passive consent is commonly used in large population health studies as it can be very costly and time consuming to obtain consent directly.

Due to a different agreement with the province of Alberta, the EDI uses active consent in Alberta. This means parents are sent an information letter home from school and need to send back a signed consent form to indicate their willingness to have their child’s data collected.

We encourage all parents who have additional questions to contact us directly. We also have a FAQ section to help answer some common questions parents have.

The EDI is voluntary

Participation in the EDI is completely voluntary and we respect parents’ decision to withdraw their child from the data collection. If you do not wish for your child to be a part of the EDI please contact your child’s school.


Children’s data are anonymized

Children’s names are not shared with the Offord Centre and are replaced with a unique EDI identification number. We also do not collect children’s home address. The only personal information we receive are children’s gender, birth dates, and postal codes.

The EDI does not report on individual children

No individual child is identified on the EDI. Results are grouped and your child’s score will be combined with many other children from your community or neighbourhood. We require a minimum number of children in a certain area in order to report EDI scores. This ensures there is no way for your child to be identified in the data.


Protecting EDI data

Electronic data are securely stored on password protected computers in locked offices. Only a limited number of research staff has security access to the data. Hard copy files are stored in a locked, restricted access room.

The EDI has ethics approval

Since 1998 the EDI has received ethics approval from the McMaster ethics board (now called the Hamilton Integrated Research Ethics Board). The project undergoes yearly approval and must meet certain conditions to maintain that approval. For more information on ethics at McMaster please visit