The Ministry of Justice is reviewing the Arms Act 1983 this year, and any potential changes to the legislation are likely to be announced late this year.
University of Otago (Wellington) public health researcher Dr Lucy Telfar-Barnard said more than 1000 people died and 2115 people were admitted to hospital as a result of firearms-related assaults, accidents and suicides between 2000 and 2018.
The new study found firearms injuries were costing the health system an average of $1.48m per year — a total of $28.2m over the past 19 years.
It was also costing the country a further $321m in terms of years of life lost — the financial costs of the deaths.
Dr Telfar-Barnard said more than 80% of those admitted to hospital needed surgery, most of the injuries from accidents.
Of the deaths, most were from suicide (819 deaths), followed by assaults (147 deaths) and accidental deaths (48).
Most of those who died were men, with mortality rates highest in those of European ethnicity, followed by Māori.
Māori were three times more likely to be victims of firearms homicides than Europeans, and Māori and Pacific peoples were 2-3 times more at risk of being admitted to hospital as a result of assault with a firearm than Europeans.
Firearm ownership in New Zealand was regulated by the Arms Act, which had been amended several times, major changes being made after 13 people were shot dead in Aramoana in 1990, Dr Telfar-Barnard said.
In 1992, the government introduced a raft of changes, including the requirement for character checks for those applying for firearms licences.
The most recent changes were made following the Christchurch mosque attacks in 2019, when the government banned military-style semi-automatic firearms and set up a firearms registry.
The study starkly highlighted the human and financial costs of gun ownership, and demonstrated the importance of having strong firearms regulations in place, she said.
"Firearms are placing an extensive health burden on the country, not only in life years lost, but also in years of life affected by disability."
Previous research had found policies restricting firearm ownership were associated with a reduction in firearms-related homicides and suicides, Dr Telfar-Barnard said.
She was concerned the government review might result in a relaxation of some of the regulations.
The high cost of firearms injuries underlined the importance of maintaining and strengthening firearms restrictions, and of improving education on firearm safety, she said.
"We are calling for firearms regulations to be maintained or strengthened.
"We would hope that the findings from this research paper are taken into consideration during the review.
"We are seeing an increase in deaths from assault with firearms, and so any relaxation of firearms regulations would be counter to decreasing that."
