The study of 18 district health boards found length of stay declined in the ED by 1.1 hours and in the hospital overall by 7 hours and ED crowding reduced by 27 per cent. The only negative effect was a 1 per cent increase in the rate of re-admission to a ward within 30 days of discharge, suggesting some patients had been moved out of hospital too soon.
Health Minister Jonathan Coleman has welcomed the reduced patient deaths and other findings of the research, to be presented at an emergency medicine conference in Queenstown today by emergency physician Dr Peter Jones, of Auckland University and Auckland City Hospital.
Dr Coleman said: "We know that when ED and wider hospital teams work collaboratively towards achieving the target then real improvements in patient care can be achieved."
The target is that 95 per cent of ED patients are discharged, admitted to a ward or transferred within six hours of their arrival.
The latest report available yesterday showed that 10 district health boards were at 95 per cent or better and 10 were between 89 and 94 per cent.
The target was introduced by the then-new National Government in 2009, after emergency physicians blind-sided Labour ministers in 2008 with the estimate that overcrowded hospital wards and EDs were killing about 400 people a year.
The doctors said patients were at risk of not having antibiotics or heart-attack treatment started quickly enough or could simply be overlooked when ward "access block" left EDs overcrowded.
National had campaigned against overcrowded hospitals, particularly North Shore Hospital, which was the subject of criticism in a special investigation by the then-Health and Disability Commissioner Ron Paterson.
No extra funding came with the ED target, but the researchers found DHBs shuffled budgets to spend $52 million on achieving it, mainly by hiring more staff in the ED.
Jones told the Herald he started out biased against ED targets because of the "gaming" that occurred in the UK where he witnessed the skewed effects of its four-hour target which - unlike New Zealand's version - came with financial incentives and penalties.
"The chief executive's job was on the line."
"I got hauled over the coals on my first day for not letting a patient, who was dying, go to a ward. They needed resuscitation and did not need to move. Instead of being thanked for saving the patient, I got told off for a breach of the target."
His research group has, however, found some evidence of data irregularities, and the minister's targets regime has been criticised by the Opposition and some medical groups for focusing public health managers on specific areas of health care, to the detriment of others, such as mental health and follow-up eye appointments.
Co-researchers including Dr Linda Chalmers wrote, after interviewing key staff at four DHBs: "Hospital respondents in all sites reported gaming responses to the target which included stopping the clock prematurely in the ED when patients had not yet been discharged or admitted, and moving patients from the targeted ED environment to acute assessment wards or observation status/beds when alternative avenues of avoiding target breaches were exhausted.
"Respondents reported that patients were sometimes transferred out of ED into wards when beds were not available in the wards."
Jones said it was difficult to analyse whether the admissions to acute assessment wards were appropriate, but they probably were.
The findings
• 700 fewer deaths in emergency departments in 2012 than would have been expected if pre-target trends had continued
• 1.1 hours - reduction in average length of stay in EDs 2006-2012
• 7 hours - reduction in average length of stay in hospital
• 1% - increase in re-admission rate to a ward within 30 days of discharge