The Ministry of Health intends to change from the smear test-based screening programme - where women are tested every three years - to a five-yearly human papillomavirus (HPV) primary screening programme.
However, scientists Brian Cox and Mary Jane Sneyd, from Otago's Hugh Adam cancer epidemiology unit, have just published research which assessed Australia's change to five-yearly testing.
They found Australia had made an error and overstated its effectiveness.
Dr Cox urged the ministry to abandon plans to introduce it and rethink its proposal.
However, ministry national screening unit group manager Astrid Koornneef said it remained committed to implementing HPV testing from 2021.
''We want to reassure New Zealand women that plans to introduce HPV primary screening are based on rigorous research and a thorough review of the scientific evidence,'' Ms Koornneef said.
''Changing the primary test in New Zealand is predicted to further reduce cervical cancer deaths by 16% in unvaccinated women and 12% in vaccinated women.''
Prof Cox and Dr Sneyd's article suggested following Australia's could produce a 39% increase in long-term cervical cancer incidence.
Ms Koornneef questioned the Otago researcher's findings.
''The conclusions of Prof Cox's article were based on an incorrect assumption that a negative HPV test only provided the same protection over time against cervical cancer as a negative cytology test,'' she said.
''The HPV test is a sensitive test designed to pick up the virus which causes 99% of cervical cancers.
Prof Cox said last night he stood by the research findings, and said a similar Finnish study had found the same results.
''It is not an assumption, but published evidence.''
''The commitment [of the ministry] may be driven by a difficulty to face the prospect that the large amount of money and time already invested in changing the screening policy may have been misplaced and the risk of management review of the policy change process.''
He said the ministry's predictions of the efficacy of HPV testing was based on a simulation study which had been shown to be seriously flawed.
Cancer Society medical director Chris Jackson said it was important New Zealand stayed on top of all recent international reports, and experience from countries which had switched to HPV-based screening.
''This will ensure New Zealanders continue to have the very best protection against cervical cancer as possible,'' Dr Jackson said.
''Our own health promotion committee undertakes regular reviews of the international literature, and will be able to review Prof Cox's research at its regular meetings.''
In the meantime, parents should ensure children were vaccinated, and all eligible women should accept the three-yearly invitation to screening, he said.
