Dr. Carolyn Snider, an emergency physician and scientist with St. Michael’s Hospital’s MAP Centre for Urban Health Solutions, walks through the emergency department at St. Michael’s in downtown Toronto on March 26.Laura Proctor/The Globe and Mail
Mandating hospitals to record homelessness among their patients dramatically improved the health care system’s ability to identify such patients, a new study has found, laying the groundwork for improving care and alleviating strain on the system.
The study, authored by researchers at the MAP Centre for Urban Health Solutions at St. Michael’s Hospital in Toronto, is part of a push to recognize the relationship between housing and health, both to improve health outcomes for homeless people and to address the disproportionate impact they have on the system.
The researchers studied the impact in Ontario hospitals of a 2018 mandate from the Canadian Institute for Health Information (CIHI) that required hospitals to record homelessness among patients admitted for both emergency and non-emergency visits.
Lucie Richard, the lead author of the study, said the mandate helped identify about one in two homeless patients, more than double the number before the CIHI policy update.
“Having data that’s specific to this population can really help us,” Ms. Richard, a senior research associate at the MAP Centre, said in an interview. “Every time we put in a new policy or a program that’s targeting the specific population, you can evaluate the impact of it more easily.”
Each time a patient visits a hospital in Canada, a medical coder records information about their condition using a series of standardized letters and numbers – for example, J18.9 for pneumonia or E119 for diabetes without complications. There are also categories known as ‘Z’ codes, which are used to capture non-medical factors such as unemployment, child welfare issues and homelessness. The code creates a vivid picture of a patient’s well-being and the factors influencing it.
The codes come from the World Health Organization’s International Classification of Diseases. Homelessness has long been listed as Z59.0 but hadn’t been widely used in Canada.
Before the CIHI mandate to use that code, there would often be a blank space next to a person’s housing status. Coders were previously encouraged to record homelessness when identified in the file by doctors and other workers in the health care system, but it wasn’t mandatory, which meant it was often overlooked.
Code Z59.0: diagnosing the toll of homelessness on health care
The mandate meant housing status was recorded for more patients, but the study found that two out of three people marked as homeless in the data were not actually homeless at the time. Ms. Richard said most of the people incorrectly identified as such had been homeless in the preceding year. Her theory is that doctors are noting prior history of homelessness, as they find it relevant to the current health care needs of the patient. Coders are seeing this information and recording it as Z59.0.
Ms. Richard added that it’s hard to know whether the increase in identifications is the result of more accurate reporting or a larger homeless population.
Stephen Hwang, an internal-medicine physician and director of the MAP Centre, said the 2018 policy has had an “enormous impact” in allowing health care providers to understand the urgent health problems facing homeless people. “Before, for example, we knew there were lots of overdoses. Now we can see just how disproportionate the impact is on homeless people.”
Although there’s always been an ability to track the data, more often than not, the information was missing “because it wasn’t mandatory, it was often ignored,” Dr. Hwang said.
Geoff Hynes, the population health manager at CIHI, has felt the impact of the policy change first-hand. Once a Z59.0 code is registered, it’s the job of his team to make sense of it.
“We can see what that whole journey looks like for homeless individuals now,” he said. “We go through the health care data and we can identify and extract cohorts of patients and look at their interactions in the health care system … what they were hospitalized for and why. Where they were discharged and why.”
The people collecting the data include doctors and nurses but also administration staff and social workers. “Someone can go to the emergency department with a broken leg and they mention to the health care worker that they’re couch surfing … that gets recorded,” Mr. Hynes said.
The data is invaluable for providing urgent and tailored care to homeless people but also reducing strain on health care facilities. “Hospital stays for this complex patient population are very lengthy and costly due to their extensive health and social challenges,” Mr. Hynes said.
The Globe and Mail reported last year that in 2023 the 100 most frequent ER users at two Toronto hospitals – recorded as having no fixed address – made 4,309 visits. That group, which represented 0.12 per cent of all University Health Network patients, accounted for 3.5 per cent of the year’s ER visits.
While shelter needs and a lack of family doctors are key reasons why homeless people rely on hospitals so frequently, it’s also because their living conditions make it difficult to follow a doctor’s care instructions, said Kristy Buccieri, a sociology professor at Trent University who researches homelessness.
“If you’re told to dress your wounds or take medication regularly and you’re staying in a shelter, you might not be able to do it,” she said. The new mandate, Ms. Buccieri said, would likely make it easier for health care providers to address the continuing needs of patients head-on to reduce repeat visits.
“There’s a lot of benefit … you can have someone in the waiting room identify what they need, there’s somebody who can help make sure they follow up on appointments and medication,” she said. “They can provide ongoing support.”
Importantly, Dr. Hwang said, the coding mandate only works to the extent that physicians inquire about a patient’s housing status while also providing them with care.
“It’s really important for physicians to be asking … and in the right way,” he said. “Instead of asking if you’re homeless, we can ask: ‘What’s your living situation like? Where are you staying?’ It’s a much better way of understanding the lives of our patients and the challenges they’re facing.”