Medical specialists are warning a change to the way women are tested for cervical cancer is risky and premature.

From 2018, three-yearly primary cervical screening tests based on cell analysis will be replaced with tests for human papillomavirus (HPV) - which causes more than 90 per cent of cervical cancer - every five years.

Announcing the change on Wednesday, Health Minister Jonathan Coleman said it was expected to reduce the number of cervical cancer deaths.

But in a strongly worded editorial, published in the New Zealand Medical Journal today, a group of specialists and researchers criticised the move as "premature and wrong".


"This decision could reduce the current level of cervical cancer protection and increase unnecessary referrals for assessment and treatment," the authors said.

"The potential for physical and psychological cost to women is unknown."

The authors, led by prominent Dunedin cytopathologist Peter Fitzgerald, said there was no argument there would be more colposcopy referrals, diagnostic biopsies and treatments as a result of HPV testing, compared with the current screening system.

"The debate is only around how much extra and whether the New Zealand health service can cope with the increased demand for these services," the authors said.

The editorial called for co-testing with both cytology and HPV screening.

The Ministry of Health consulted the sector and the public last year on changing the test.

Dr Coleman said this week while New Zealand had one of the most successful cervical screening programmes in the world, there was "always scope to further improve".

Around 160 New Zealand women develop cervical cancer each year.