The 2009 swine flu pandemic cost the New Zealand hospital sector about $31 million, a University of Otago study has found.
The researchers also found the "true cost" of the H1N1 pandemic to the New Zealand health system would be substantially higher as the study looked only at hospitals and not primary care and public health services.
Given uncertainties in the data, the range for the cost to the hospital sector was $22 million to $40 million.
The study was published in The New Zealand Medical Journal alongside a second Otago study looking at the strengths and weaknesses of the health sector's response to the pandemic - its authors lamenting the lack of a "comprehensive review" after the outbreak.
The study looking into the cost showed on average it cost $17,000 per patient (average stay six days).
For those going to an intensive care unit (ICU) it was $97,000 per patient (average stay 12 days).
The study's lead author, Associate Prof Nick Wilson, said despite the fact the swine flu pandemic was "relatively mild" compared with previous ones, it still killed 49 people, sent 1122 people to hospital and 102 were so sick that they needed ICU treatment.
Co-author Associate Prof Michael Baker said the high cost of the pandemic showed there was potentially value in further work on preventive measures, such as influenza vaccines and investing in pandemic planning and other control measures.
The second Otago University study found the response by the public health, primary care and hospital sectors was successful overall, but not without a few weaknesses.
These weaknesses inclu-ded the lack of a detailed review of the overall response and studies to identify risk factors for hospitalisation and death.
Dr Wilson said the lack of a comprehensive review was "clearly an oversight" given that future pandemics were "certain to occur".
Governments needed to be "a bit smarter" about doing reviews of disaster response, he said.
"They should not just commission reviews of disasters where it was obvious that things went badly wrong like the Pike River Mine," Dr Wilson said.
Health Minister Tony Ryall told the Otago Daily Times yesterday that the Ministry of Health carried out internal operational reviews and that he commissioned an independent external review into the response to the swine flu pandemic.
New Zealand's response was "well regarded both nationally and internationally", Mr Ryall said.
"For example, the World Health Organisation now regularly request expert technical advice from the Ministry of Health on pandemic preparedness and response," Mr Ryall said.