Factors related to vaccine uptake by young adult women in the catch-up phase of the National HPV Vaccination Program in Australia: Results from an observational study

Background: Australia commenced a publically-funded, National Human Papillomavirus (HPV) Vaccination Program in 2007 with a two year catch-up phase for females aged 12-26 years. Objective: To identify the factors associated with the uptake of the HPV vaccine (which has a recommended 3-dose schedule in Australia) by young adult women vaccinated by general practitioners and community-based programs within the catch-up phase. Methods: 1139 women who were eligible to receive the free HPV vaccine during the catch-up period were recruited in 2008-2009 (age 20-29 years at recruitment), in New South Wales, after having a normal (negative) cervical smear result recorded on the NSW Pap Test Register. Participants completed a self-administered questionnaire providing information on vaccination status, and sociodemographic and other factors. Results: Overall, 880 (77%) women reported receiving >= 1 dose of the vaccine and 777 women (68%) reported receiving >= 2 doses. In multivariable analysis (adjusting for the period for which each woman was eligible for free HPV vaccination), uptake of >= 1 dose of the vaccine was significantly associated with being born in Australia (p<0.01), being single (p=0.02), being nulliparous (p<0.01), living in a higher socioeconomic Status area (p-trend = 0.03), living in more remote areas (p = 0.03), drinking alcohol (p<0.01) and using hormonal contraceptives (p<0.01). Although vaccinated women were more likely to have fewer sexual partners than unvaccinated women (p-trend = 0.02), they were also more likely to report a prior sexually transmitted infection (STI) (p = 0.03). Similar factors were associated with receiving >= 2 doses. Conclusions: In this group, women living in higher socioeconomic status areas were more likely to be vaccinated against HPV in the catch-up phase of the national program. Although vaccinated women tended to have fewer sexual partners, they also reported prior STIs, which may be a marker of increased risk of prior exposure to HPV. The findings of this study reinforce the continuing need to prioritise equitable delivery of vaccination to various population subgroups. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.