Patients who leave hospitals against medical advice are more than three times as likely to visit emergency within a week, according to a CIHI report.

Ottawa clinicians have expressed concern about the findings of a new report that found one in every 100 hospital patients went home before they had been discharged.

The Canadian Institute for Health Information found in 2011-12, a total of 25,137 admissions or 1.3 per cent of acute hospital admissions across the country ended with patients leaving against medical advice, excluding Quebec.

About 1.1 per cent of all discharges in Ontario were against medical advice and the Ottawa Hospital, CHEO and the Montfort Hospital in Ottawa all had similar numbers to the province.

Joshua Fagbemi, one of the CIHI researchers, said they also found people who leave the hospital prematurely are more than twice as likely to be readmitted within a month and more than three times as likely to visit emergency within a week.

"This is an additional cost being brought into the health care system that could potentially be avoided," said Fagbemi.

Young men, people with mental illness more likely to leave

Self-discharged patients were more likely to be younger and male and were also more likely to have mental health issues and diagnoses of psychoactive substance abuse.

Dr. Alan Forster, the scientific director of performance measurement at the Ottawa Hospital, said the CIHI report shows the importance of health care programs that focus on people with mental illnesses or who are in vulnerable populations like the homeless.

"To me that suggests that that segment of the population isn't being managed well by our health system," said Forster.

"If people go home in the middle of their treatment in many instances, that's going to set them back … and will require more therapy and it likely reflects gaps in our health care systems ability to meet a certain population's needs."

The Ottawa Hospital is already experimenting with an outreach program to go directly to patients suffering mental illness, substance abuse and homelessness.

But Dr. Forster concedes not much is known about the other half of patients who leave who do not suffer a mental illness and suggests it is an area he says should be further investigated.

The CIHI report also looked at emergency rooms in Ontario and Alberta and found nearly one per cent of discharges were against medical advice.