Four in 10 patients are referred to A&E by their family doctors
Almost four in 10 patients who attended emergency departments were sent by their GPs between January and November last year.
Provincial hospitals tended to have the highest rate of GP referrals to their emergency departments, and in some cases 55pc of patients were sent for treatment by family doctors, figures showed.
Of those patients who were referred by their GPs, just under one in four were admitted to hospital.
The data was compiled by the Health Service Executive (HSE), and has been released at a time when emergency departments are struggling to cope with chronic overcrowding caused by an ageing population, bed and staff shortages, and gaps in primary care services - all exacerbated by a seasonal surge in illnesses.
Health Minister Simon Harris blamed the crisis on a "perfect storm" of conditions.
The HSE figures showed that 37pc of patients in emergency departments between January and November were referred by a GP.
A total of 58pc of patients who presented to Letterkenny General Hospital's emergency department in Co Donegal in November were GP-referred, while the figure was 57pc in Mayo General Hospital and University Hospital Kerry emergency departments, and 53pc at University Hospital Limerick.
GP referrals also accounted for more than half the patients in emergency departments in the Midland Regional in Mullingar, Co Westmeath, and Cork University Hospital.
All the hospitals experienced serious problems with overcrowding when the emergency department crisis peaked earlier this month, with a record 612 patients on trollies on January 3. Some of the most chronic problems were in Limerick and Cork.
A total of 23.5pc of patients referred by GPs to emergency departments were admitted between January and November. The age profile of the patients in attendance was predominantly elderly and included 89 patients who were aged 100, 98 patients aged between 101 and 105, three 106-year-olds, one 107-year-old and a 108-year-old.
The HSE cautioned that the figures were provisional.
GPs have said there is no correlation between the trolley crisis and doctors referring patients to emergency departments. GPs' groups said the overcrowding is exacerbated by the shortage of family doctors across the country, a surge in demand caused by the free GP service for children under six, and glaring gaps in the primary care facilities that are intended to help keep patients out of hospitals. Dr Liam Glynn, a Clare GP and chair of communications at the National Association of General Practitioners, said doctors acted as "gatekeepers" to hospitals.
"You would hope most people in emergency departments are referred by GPs, rather than self-referring," he said. "The more patients referred by a GP the better the system."
He said GPs strived to keep patients out of hospitals, referring only those patients most in need of hospital care.
In Dr Glynn's out-of-hours practice, Shannon Doc, only 7pc of patients seen over the Christmas period were referred to hospital, he said.
The HSE suggested those living in rural areas were more likely to call their local doctor first, rather than travel to the nearest hospital emergency department. There were more self-referrals in urban areas because emergency departments are more accessible.
Hospitals struggled to cope with a surge in patients to emergency departments in the first week of 2017. The HSE warned an influenza outbreak was a catalyst for the latest surge in visits was likely to worsen.