Background: The aim of this study was to determine the most important ways to reduce incidence of and mortality from cervical cancer by a nationally co-ordinated screening programme.
Design: Descriptive study.
Setting: The New Zealand National Cervical Screening Programme: a nationally organised and co-ordinated programme.
Sample: Women aged younger than 80 years with histologically proven primary invasive cervical cancer, including microinvasive disease, diagnosed between 1 January 2000 and 30 September 2002. Consent for access to medical records was gained for 371 of 445 eligible women (83%). A total of 359 (81%) of eligible women or their next of kin consented to interview.
Methods: Data on events prior to diagnosis were obtained from routine sources, interview, medical record review and slide reread.
Main outcome measures: Frequency of screening in the 7 years prior to diagnosis, time from abnormal smear or symptoms to appropriate diagnostic confirmation, proportion of negative smears upgraded to high grade on reread.
Results: Half of the 371 participants (83% of 445 eligible women) had not had a screening smear in the 3 years prior to diagnosis, and 80% were defined as inadequately screened. A maximum of 17% of women overall or within any defined subgroup experienced delays in follow up of abnormal smears or bleeding. Only 11% of women overall had had a high-grade smear, which was originally read as negative.
Conclusions: The most important factor in women's pathways to a diagnosis of cervical cancer was inadequate screening. While delays in diagnosis could be reduced and laboratory performance improved, priority must be given to improving uptake and frequency of screening.