The research, conducted in Dublin, found they also have 10 times greater use of unscheduled inpatient beds than people who have a home.
And far higher numbers of homeless people leave ED without being seen — with anecdotal indications suggesting they were only seeking shelter overnight or left because they were withdrawing from drugs.
The study examined the use of the ED and inpatient care at St James’s Hospital, in Dublin’s south inner city.
“We found that, in Dublin, homeless individuals have a 20-fold increased use of ED and over 10-fold increased use of unscheduled medical inpatient bed than housed individuals,” said the report.
The research, published in BMJ Open, said 80% of adults in emergency accommodation or sleeping rough in Dublin are under the age of 44.
In addition, up to 70% of homeless people report having used illegal drugs with over half reporting injecting drugs.
The study, led by Cliona Ní Cheallaigh of St James and Trinity College Dublin, said that homeless patients are much more likely to leave ED without being seen (41% v 16%).
“Anecdotally, some of the homeless individuals who leave without being seen may have simply been seeking shelter for the night in the ED waiting room, with others requiring medical attention leaving due to withdrawal from alcohol and/or opiates and attention deficit disorder-related difficulties with waiting,” it noted.
It said homeless people account for a “grossly disproportionate” amount of inpatient bed days relative to their proportion of the catchment area.
The report, made available through the Health Research Board, said diseases related to alcohol and drug use are more common in homeless patients and that seizures are more common.
“In this study, we demonstrate that homelessness is also associated with a dramatic increase in the per capita use of costly unscheduled acute healthcare,” the report read.
“A failure to address the structural causes of homelessness results in increased costs to society through increased use of healthcare, in addition to social care.”