If your study is a clinical trial regulated by Health Canada, you are required by Health Canada to retain study documents for 25 years after trial completion. UBC now offers records management/storage services at a reasonable cost. Iron Mountain and Access also offer record management services.
If your study is not a clinical trial, you should retain your records per institutional requirements. For UBC, this is five years after study publication or presentation.
You must close the study with the PHC REB, and if you have received outside funding you usually need to report back to the funding agency as well.