Will vaccinated women attend cervical screening? A population based survey of human papillomavirus vaccination and cervical screening among young women in Victoria, Australia
Introduction
Over the last 50 years, screening for cervical cancer precursor lesions using Pap testing has been the main method adopted for the prevention of cervical cancer. In Australia, as in other developed countries where highly organised screening programmes have been instituted, the reduction in incidence and mortality has been dramatic [1]. Because screening using Pap testing has imperfect sensitivity, it requires regular attendance from participants for maximum impact [2]. The development of highly efficacious prophylactic human papillomavirus (HPV) vaccines now provides for a new primary prevention strategy for cervical cancer. When delivered prior to exposure, both available vaccines prevent infection with HPV 16 and 18, the two oncogenic HPV types responsible for 70% of cervical cancer globally and approximately 50% of high grade cervical lesions [3], [4].
Australia implemented a broad catch-up HPV vaccination programme between 2007 and 2009, which provided the three-dose course of quadrivalent HPV vaccine (Gardasil™) free of charge to all women aged 12–26 years. The vaccine is now provided free only as part of the school-based vaccination programme for girls aged 12–13 years.
One of the key messages in promoting the National HPV Vaccination Program was that vaccinated women would still need to attend for cervical screening, given that the vaccine does not protect against all cervical cancer. This message was stressed in mass media advertising and written materials. Unfortunately over the last decade cervical screening participation in young women has already been in gradual decline in Australia, as in other countries [5], and it is of concern that women who are immunised against HPV may not go on to screen appropriately. In Victoria, the second most populous State of Australia, Pap Screen Victoria undertakes the educational and health promotion arms of the National Cervical Screening Program which encourage women to attend regularly (every 2 years as per national policy) and appropriately for screening across the recommended age range from age 18 (or 2 years after sexual intercourse, whichever is later) to 69 years.
In the final year of the catch up HPV vaccination programme in Australia, the Centre for Behavioural Research at the Cancer Council Victoria commissioned a population based Computer Assisted Telephone Interview survey focusing on young Victorian women in order to measure their self-reported vaccination uptake and intentions, their confidence in their recall of their vaccination schedule, their barriers to vaccination or course completion, their understanding of the interaction between vaccination and screening, and their future screening intentions.
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Methods
We commissioned the Social Research Centre to conduct a population based CATI survey in May 2009 and interview 1000 Victorian women aged 18–69 years. Methods were as per previous waves of the regular CATI surveys [6] but in this study we over-sampled women aged 18–28 years (i.e. women who had been eligible for the vaccine during the free catch up programme). The findings for the 234 women in this age group are presented here.
The survey instrument was based on previous waves of the study, with
Results
The response rate for eligible households was 62.4%.
Demographics
Characteristics of the sample are summarised in Table 1. Of the 234 women, 87% spoke English as their main language at home, 30% had completed tertiary education and 18% were married. No women of Aboriginal or Torres Strait Islander origin were identified in the sample. Most women lived in the Melbourne metropolitan area (67%). No woman in our sample had undergone a hysterectomy.
HPV vaccination awareness and coverage
Nearly all of the young women had heard of ‘…a vaccine to prevent cervical cancer, the human papillomavirus or HPV vaccine’, with only 12 women (5%) unaware of it. Questions about the vaccine were only asked of the 222 who had heard of it.
Nearly three-quarters (73.9%) said they had started the vaccination programme (includes 1.7% unsure of number of doses they had received), 69.1% had received two or more doses and 55.9% had received all three doses. Among those who commenced the course, 5% (n =
Understanding of Pap screening and HPV vaccination
Among our participants, 218 women (93%) had heard of Pap tests and, of these women, 60% (n = 131) had ever had one. Of those women who had heard of Pap tests, 12% indicated a Pap test was for early detection of cervical cancer and 30% reported just that it detected cervical cancer. The others gave answers that were very vague, incorrect or gave a correct answer but also thought the test could detect other problems.
Women were presented with five statements about the cervical cancer vaccine and
Future Pap test intentions
The young women who had not yet had a Pap test (n = 87) reported high levels of negative feelings about Pap tests and confusion about whether they needed one, but none indicated that they believed they did not need a test because they had been vaccinated. However 8% (n = 13) of vaccinated women did agree that ‘Having had the vaccine makes me less likely to have a Pap test in the future’ and 17% (n = 8) of the unvaccinated women agreed that ‘Knowing the vaccine is available makes me less likely to
Discussion
We found that the HPV vaccine coverage achieved in adult women in Victoria, even prior to the conclusion of the catch up vaccination programme, was substantial and was highest in the youngest women. The young women in our study were aware that Pap tests are needed after vaccination; however some women were unclear what the limitations of the HPV vaccine are, believing that it may be used to treat disease and can potentially prevent all cervical cancers. Many young women were also uncertain
Conflict of interest
The authors have no personal or financial conflict interest. The study funder had no interference in the study design, data collection or writing of the manuscript.
Acknowledgements
The authors would like to thank Michelle Grainger for co-ordinating the survey and for the data analysis. The study was funded by PapScreen Victoria and conducted by the Social Research Centre.
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