We handed in everything we can think of. Medical certificate, medical letters (From 4 doctors. 3 from our home country that was treating him before with an alternative medication which didn't work, and 1 from his doctor in Canada that have been treating him), medical history, medication history, treatment history, proof that he cannot be treated in our home country, proof that he has tried alternative treatments in our home country but didn't work, etc.
Also, I have a friend that also applied for H&C for her own medical reason. She had a rare condition that wasn't common in her country so there wasn't any treatment. She handed in everything like I did. Every single proof and evidence. There was absolutely no reason her to be refused. She had a valid work visa, she proved to the officer about everything. But 5 months ago, she got refused 4 DAYS after she got her AIP. So she had to go back to her home country. 3 months ago, she came back to Canada with another visa because she had a seizure in her country when she stopped getting her usual treatment and medications.