This would require people fit enough to walk through the doors to see a GP first - and meet the cost, Otago District Health Board chief executive Brian Rousseau said yesterday.
Patients identified as requiring specialist care would then be referred to the emergency department.
Patients referred by their own doctors, or who were transported to hospital by ambulance or helicopter, would continue to have direct access to the emergency department.
There were various ways the patient filter system might work, Mr Rousseau said.
One was to create a GP clinic at the hospital, as Dunedin people still gravitated to the hospital for primary care, particularly after normal business hours.
There was anecdotal evidence they went to the hospital because the treatment was free, and because it was the traditional place to receive emergency care.
The decision to revisit the 2006 proposal was made because of the "inordinately high" number of people going to the emergency department instead of to a GP, Mr Rousseau said.
In the year ended June 30, 36,976 patient visits were recorded at the department, almost 900 more than the previous financial year.
It was estimated at least 20%, or more than 7400, could have been made to a GP instead in the 2007-08 financial year.
A three-week survey in April which took snap samples of attendance during the day and evening - but not overnight or at the weekend - showed about half the 153 surveyed had conditions classified as non-urgent.
While patient visits had dropped from more than 40,000 in 2002-03, Dunedin Hospital's figures were still too high relative to the population, Mr Rousseau said.
"This has been a long-standing issue. Our strategy of trying to educate people to go to a GP first is obviously not working.
"It is time to try something else."
The high attendance strained the board's financial, staffing and space resources, he said.
Ministry of Health approval would have to be given for a GP clinic to be created in a district health board facility, he said.
Ministry officials are studying the proposal, which would be returned for consideration by the boardwithin two months.
Mr Rousseau said there would be community consultation on the scheme.
That would include "sorting out the after-hours situation for doctors, too".
The proposal was not well received by the public in 2006 and the Association of Salaried Medical Specialists labelled the consultation process "a farce".
Attendances at Dunedin Hospital emergency department. -
2002-03: 40,392
2003-04: 37,956
2004-05: 37,126
2005-06: 36,851
2006-07: 36,078
2007-08: 36,976
