An evaluation of the National Cervical Screening Programme Otago site

To evaluate progress of the Otago Cervical Screening Programme towards achieving its goal of reducing cervical cancer incidence and mortality using data routinely collected by the National Cervical Screening Register (NCSR), and to investigate whether all data required for this task are available from the NCSR.

Non-identifying data for Otago women aged 20-69 years were obtained from the New Zealand National Cervical Screening Register for the period 1 July 1993 to 30 June 1996. For each five-year age group, proportion screened in three years, short interval re-screening estimates and age-specific reporting rates for squamous atypia of uncertain significance (ASCUS), low-grade intraepithelial lesions (LGIL) and high-grade intraepithelial lesions (HGIL) were calculated. Age-specific reporting rates were also calculated for 20-69 year-old New Zealand women for the same period and compared to the Otago rates.

The proportion of eligible women screened was 82.5%, slightly less than the target 85%. Women aged 55 years or more were underscreened, short interval rescreening was more common among younger women, age-specific reporting rates for ASCUS, LGIL and HGIL had increased since 1991/92, and the rate of HGIL was higher than expected in the 20-34 year age group.

In order to maximise the effectiveness and efficiency of the Otago Cervical Screening Programme, it is recommended that participation amongst older women be increased and frequent screening be reduced in the younger age groups. Unexpected elevated rates of HGIL amongst 20-34 year-old women were not adequately explained and require further investigation. Not all data required for an outcome evaluation were available through the NCSR.