Three-yearly cervical screening found to reduce the incidence of cervical cancer
New Zealand evidence shows that population based cervical screening is beneficial for the people it is targeted at,
National Cervical Screening Programme (NCSP) clinical leader Dr Hazel Lewis said today.
Dr Lewis was commenting in response to a recent article published in the British Medical Journal, Outcomes of screening
to prevent cancer: analysis of cumulative incidence of cervical abnormality and modelling of cases and deaths prevented.
The article raised issues over the cost effectiveness and benefits of screening programmes in general, and cervical
screening in particular.
"Recent New Zealand data published by NCSP shows that with regular three-yearly screening, the chances of developing
cervical cancer are reduced from a one in 90 chance to a one in 570," said Dr Hazel Lewis.
"Furthermore, overseas studies reviewed by the NCSP support our findings that when women have cervical smear tests every
three years as part of a screening programme, their chance of getting cervical cancer can be reduced by over 90.
The National Health Committee (NHC), whose report Screening to Improve Health in New Zealand: Criteria to assess
screening programmes was released this week found "that screening has the potential to prevent the development of
disease, prevent premature death and disability and to improve quality of life".
It also noted that screening programmes have associated costs and the potential to cause harm. Because of this inherent
risk the NCSP has, at the heart of its operations, the ethical obligation to ensure that the screening programme can
deliver the potential benefits and minimise the potential harms.
Dr Lewis said given the history of cervical screening in New Zealand, there is a very high level of public interest in
the effectiveness and safety of the NCSP. The Gisborne Inquiry generated some very specific recommendations on changes
needed to the operation and ongoing monitoring of the NCSP.
"We acknowledge that there are limitations and risks associated with screening, as well as benefits, and no programme
can guarantee 100% effectiveness. This is because screening refers not only to the initial test but also the sequence of
events that comprise the screening pathway."
"However, New Zealand's screening programmes are at the forefront in the implementation of quality standards and
monitoring in the health sector."
New Zealand women show a strong commitment to the NCSP with more than 90% of eligible women aged 20-69 years enrolled in
the programme.
Since the programme began in 1991 there have been significant reductions in both the rates of disease and deaths from
cervical cancer. In the 10 years from 1987- 1997 cervical cancer rates dropped by 39%. Over the same period the death
rate from cervical cancer dropped by 44%.
To assist women to make informed choices about cervical screening the NCSP publishes up to date information, which is
made available to women through their smear takers and the NCSP Website.