OTTAWA -- New numbers released Wednesday show close to 14,000 Canadians have been killed by opioids over the last four years and more than 17,000 people have been hospitalized for opioid-related poisoning.

The data is in a new report from a national advisory committee struck to study the epidemic of opioid overdoses in Canada.

Canada's chief public-health officer, Dr. Theresa Tam, and Saskatchewan's chief medical health officer, Dr. Saqib Shahab, issued a joint statement saying many of the deaths were caused by Canada's illegal drug supply being contaminated with toxic substances.

The say fentanyl and other very potent synthetic opioids continue to be a major cause of hospitalizations and deaths.

The data also shows thousands of Canadians continue to have non-fatal overdoses each year and hundreds of thousands more are affected by problematic substance use.

In their statement, Tam and Shahab say the opioid overdose crisis is a complex problem that will take time to turn around.

"To have a significant and lasting impact, we need to continue working together on whole-of-society changes," they say. "This includes addressing the stigma that surrounds substance use, implementing further harm-reduction measures and reducing barriers to treatment. It also means continuing to work together to better understand and address the drivers of this crisis, such as mental illness, and social and economic factors that put Canadians at increased risk."

Western Canada continues to be the most affected by the opioid crisis, but Ontario has also seen a rise in opioid-related deaths, according to the data.

Also, 94 per cent of opioid deaths in the first six months of this year were accidental, the Public Health Agency of Canada says.

This report by The Canadian Press was first published Dec. 11, 2019.