People living in extremely poor housing conditions face the same health risks as those who are homeless, a study by researchers at Toronto's St. Michael's Hospital suggests.

The report, Housing Vulnerability and Health: Canada's Hidden Emergency, revealed that for every person in Canada who is homeless, another 23 live in housing that is unsafe, crowded or costs more than 50 per cent of their income.

"Before now, researchers and decision-makers have often thought of these groups, the homeless and the vulnerably housed, as two distinct populations, with two different levels of need," said Dr. Stephen Hwang of St. Michael's Hospital in Toronto, the principal investigator of the report.

"This study paints a different picture."

The government estimates there are at least 150,000 homeless people across Canada. (Frank Gunn/Canadian Press)

Hwang told CBC News that the study revealed that "perhaps we're focussing too much on the homeless to the neglect of the vulnerably housed."

"There needs to be a housing strategy," he said.

The number of homeless people has been previously pegged by the government at 150,000, but advocates think the number is higher. Around 17,000 shelter beds are regularly available across the country.

About 400,000 people in Canada are estimated to be vulnerably housed.

The study tracked 600 homeless and 600 vulnerably housed people in Toronto, Ottawa and Vancouver over a two-year period.

It only looked at the vulnerably housed at the extreme end of the spectrum, Hwang said, including those living in rooming houses, single-room occupancy hotels and illegal basement apartments.

The report found that of the total people studied, more than half have been diagnosed with a mental health problem.

Hwang said the percentages were similar for both groups — the homeless and vulnerably housed.

As well, around a third of those studied suffer from arthritis, 30 per cent suffer from hepatitis B or C and 23 per cent have asthma.

Their lifespan is about seven to 10 years shorter than for the general Canadian population, the study found.

More than a third have been assaulted in the past year, and more than half have visited an emergency department, also in the past year.

With files from The Canadian Press