More patients with life-threatening injuries are expected to be flown straight to high-tech hospitals to try to save more lives.
New Zealand's death rate from major trauma is 50 per cent higher than in the best-performing places - about 9 per cent die here, compared with 6 per cent in Victoria.
The figures are revealed in the first annual report of the NZ Major Trauma Registry and Clinical Network.
A key way of saving more lives is to send patients straight to the right hospital, the one with the high-tech equipment and staff their injuries demand, rather than first taking them to the nearest base hospital.
The report found that in the North Island 21 per cent of patients were transferred to one or more hospitals before they received definitive care.
Major trauma is defined as a potentially life-threatening injury. Most North Island district health boards contributed data for the June 2016 year, recording 1301 cases.
When the South Island is added, a national tally of about 2000 cases is expected.
Fifty-two per cent of the major trauma cases in the North Island were caused by vehicle crashes, 28 per cent by falls, 8 per cent by assaults and 12 per cent by undefined "other" causes.
The report says 55 per cent of patients had arrived in hospital within the first "golden" hour, and 87 per cent within two hours.
But the national clinical leader of the network, Professor Ian Civil, a surgeon at Auckland City Hospital, said the golden hour concept wasn't helpful because each type of injury had its own ideal time for maximising survival.
"If you're stabbed in the heart, you don't have a golden hour; you've got a platinum 10 minutes."
He said ambulance services were about to implement new guidelines intended to deliver patients to the hospital they needed for definitive care. At present, patients were sometimes taken to a local hospital when this wasn't ideal.
"Delays are associated with increased complications and even death. When you get into a hospital, even if it's recognised early that you need to be transferred, there are lots of delays in the system - more than for the transport time. It is often a number of hours of delay in getting to the definitive hospital."
"For example, if a patient in Whakatane is hit on the head by an axe and has a bit of brain coming out of the head, they need a neurosurgeon.
"There's no point taking them to Whakatane Hospital or Tauranga or Rotorua Hospital. They don't have neurosurgeons. They need to go to Waikato Hospital."
Another example Civil gave was a patient with a "mangled extremity", typically a fractured leg, with soft-tissue and circulatory damage. Such patients needed to be in a hospital with a plastic surgery unit, which could be the difference between amputation and saving the limb.
"We don't think there's going to be any substantial increase in overall costs and these patients are going to get to the definitive hospital in due course anyway as long as they survive."