Professor Drew Richardson, of the ANU and Australian College for Emergency Medicine, said unacceptably large numbers of patients in the ACT, Northern Territory and South Australia were experiencing dangerously long stays in emergency departments.

ANU researchers contacted all accredited emergency departments in Australia on September 3 to find out how many patients were being treated and whether they were waiting for inpatient beds.

The results were not broken down by individual hospitals and the ACT's findings were grouped with South Australia and the Northern Territory. In South Australia and the territories, 46 out of 302 patients had been waiting in excess of 24 hours for admission to a ward.

''There's been an increase in the number of patients waiting for beds - quite a frightening number,'' Professor Richardson said. ''I'd particularly like to emphasise the dangerously long ED times of over 24 hours.''

Western Australia EDs had an average of 0.6 patients who had been waiting longer than 24 hours for admission and NSW hospitals averaged 1.3 per ED.

Changes are due to begin in The Canberra Hospital emergency department today, which include the opening of four additional beds and a new process which will involve patients being seen more quickly by doctors. Six more beds will also be opened in a medical ward which will allow quicker admission.

Professor Richardson said Western Australian hospitals had improved over the past three years after the introduction of a four-hour target for having patients treated and admitted or sent home.

There had also been improvements in Queensland, Victoria and Tasmania over the past year but things had deteriorated in the three bottom-ranked jurisdictions.

Professor Richardson said other states had made changes to relieve pressure.

''Other jurisdictions have gone with international best practice. They've reviewed how many beds they've got and how those beds are distributed,'' he said. ''They've introduced protocols that moved people to the wards in a more timely fashion, they've got a proper winter bed management plan.''

Professor Richardson said the territories and South Australia had failed to embrace the same changes.

In an election debate yesterday, Chief Minister Katy Gallagher said the government had increased funding for the emergency department by 146 per cent.

''The health system can't be fixed overnight, it takes a long time to address areas of pressure and the emergency department will not be fixed by necessarily investing only in the emergency department,'' she said. ''One of the biggest pressures is how many [hospital] beds we have. We had 114 beds taken out of the system when we came to government and we had to replace them.''

Opposition health spokesman Jeremy Hanson said the report provided further evidence of the ''shocking state'' of ACT emergency departments.

''It's clear that only a change of government will fix the state of Canberra's health system,'' Mr Hanson said.