If your doctor is in private practice, you have the right to tell your doctor that you do not consent to your medical information in his file being disclosed to the EHR, and your doctor has to follow that instruction. 

Already, health authorities often use large centralized systems, and if you see a physician at a clinic, or get a test done at a laboratory or imaging centre operated by a health authority, you do not currently have the right to tell the health authority that it cannot keep your medical information in its systems. This is because physicians are required to keep a record of their consultations and treatments, and health authorities also must follow this requirement.  Even this more limited disclosure into a shared record system within a health authority can be a privacy concern for some patients.

You can put a disclosure directive on your file, to limit who will have access to your records or see certain parts of the information.

You do not have the right to refuse to have your prescription information put into PharmaNet and from there into the EHR. This is because the province passed a law requiring that all prescription information must be put into PharmaNet. 

You do have the right to tell private labs and private imaging centres that you do not want your information disclosed to the provinces EHR system.