Thousands of lives are believed to have been saved by a six-hour wait time target for hospital emergency departments, which researchers say has helped halve the number of ED patient deaths.
Findings released today in the New Zealand Medical Journal also reveal that EDs are running more efficiently than before the Government introduced the target in 2009; patients are now waiting around three hours less to be admitted to a ward.
The findings have been heralded as "extraordinary" by researchers.
Dr John Bonning, chairman of the NZ Faculty of the Australasian College of Emergency Medicine, said the target had been met with scepticism by many ED doctors when it was first introduced.
"Now we all very much buy into the target: it creates quite a bit of pressure on us to perform, to refer early, to make sure that we are doing the right thing by patients and to not miss anything critical, but we are comfortable with it," he said.
"Certainly, some of us were sceptical about these targets, and some non-emergency people still are to a degree, but it's resulted in an improvement in care, not a worsening."
Bonning, who is also the clinical director of Waikato Hospital's ED, said the improvements were despite an increase in the number of patients and complexity of cases.
The wait time target required that 95 per cent of patients who arrived at ED were either discharged or admitted to hospital within six hours.
The latest quarterly report card showed 13 out of 20 district health boards were now achieving the target; meaning nearly 94 per cent of patients across the country weren't waiting any longer than the target time.
A nationwide study published in the journal, led by Dr Peter Jones of the University of Auckland, found patients weren't receiving lesser care as a result.
The study analysed nearly 5.8 million ED presentations between 2006 and 2012 and more than two million elective admissions from 18 DHBs.
It calculated a 57 per cent drop in ED patient deaths and 28 per cent less crowding in emergency departments.
Patients were waiting an hour less to be admitted to ED and nearly three hours less to be admitted to a hospital ward.
There had been a marginal improvement, three minutes, in how long admitted patients waited to see an ED doctor.
In an editorial , Otago University emergency medicine researcher Professor Mike Ardagh noted the rate of deaths had remained unchanged among those discharged home from the ED, or those admitted from the ED to a hospital ward.
This suggested the target was not being achieved by shifting the risk to areas other than the ED.
But the most dramatic finding was the significant fall in mortality among ED patients, equating to 700 fewer deaths in 2012 alone, Ardagh said.
"This is an extraordinary finding."
He labelled the reduced waiting times an "important and useful intervention in New Zealand healthcare".
The Ministry of Health's clinical director of emergency management, Dr Angela Pitchford, also pointed to other findings showing an overall reduction in hospital stays, an increase in available beds, and extra capacity created for more acute admissions.
But Pitchford said there was always more that could be improved, particularly around getting patients from the GP to hospital and then to specialist areas within hospitals.
Health Minister Jonathan Coleman was pleased at the findings, which proved the target "actually has a real benefit for patients".
Coleman said there were no plans to push the target up to 100 per cent.
Jones nonetheless noted that "failure" to meet the current target didn't appear to matter, as the changes we observed were achieved without reaching 95 per cent.
"What matters is improving the throughput of patients from ED to the hospital by making whole system changes," he told the Herald.
"If this occurs then target performance will improve naturally."
This required "whole of hospital" approach, simply focusing on the ED missed the point, as the main cause of ED crowding and its associated harms was delay in moving patients who required admission to hospital onto the ward.
It required buy-in and co-operation from inpatient specialists and engagement from hospital management, Jones said.
"If the Ministry of Health puts too much pressure on DHBs, or DHBs put too much pressure on staff, to meet the target and this pressure is not matched with appropriate resources to enable real improvements in care, then people may start manipulating data or moving patients from ED before their emergency care is complete.
"If this happens potential benefits may be lost and patients may be harmed."
Some patients required more than six hours in ED for good clinical reasons, which was why the target was 95 per cent rather than 100 per cent, he said.
"It would be a complete disaster to make the target 'harder', like raising it to 100 per cent, as this is unachievable and potentially dangerous."
Jones acknowledged the Health Research Council for funding the research, which would not have been possible without the council's support.
By the numbers
At 90 per cent of hospitals, a new study has suggested the six-hour wait time target:
• Reduced ED patient deaths by 57 per cent.
• Slashed ED crowding by 28 per cent.
• Reduced the time ED patients waited to be admitted to a hospital ward by nearly three hours.
• Reduced the time patients waited to be discharged ED by more than an hour.