HPV self-sampling and follow-up over two rounds of cervical screening in Australia - the iPap trial.

OBJECTIVES: Previously, based on 6 months of follow-up, we showed that HPV self-sampling improved participation in cervical screening compared to a reminder letter for Pap testing for never- and under-screened women. Here, we report follow-up and related screening outcomes for women who participated in the initial self-sampling over two screening rounds. SETTING: The randomised controlled trial was conducted in Australia. METHODS: Never- and under-screened women were randomly allocated to the HPV self-sampling or the reminder for Pap test arm and followed at 6 and 36 months since the kits were first mailed. RESULTS: The first round of HPV self-sampling kits were mailed from May-July 2014 to 12 572 women. After 36 months, 19% of never-screened and 9% of under-screened women returned a kit for HPV testing; 2.7% were HPV 16/18 and 5.8% non-16/18 HPV positive. Compliance with first round follow-up was 84% (95% CI: 77.1-89.5%). Non-compliant and cytology triage negative women were mailed another kit at 12 months. Compliance at 12-month follow-up was 59.3% (49.4 to 68.6%). Of 37 women with a 12-month repeat HPV, 70% were positive. Of women who tested negative for HPV in the first round (n = 1573), 25% attended regular screening in the next round and none had CIN2 + detected. The overall prevalence of CIN2 + was 8.5 per 1000 screened (4.8 to 13.9 per 1000). CONCLUSION: While self-sampling can successfully engage women, compliance with repeat testing may require monitoring. The clinician-supported self-collection pathway now in use in Australia will likely improve women's engagement with follow-up.

Cervical Abnormalities Are More Common among Indigenous than Other Australian Women: A Retrospective Record-Linkage Study, 2000-2011.

Indigenous Australian women have much higher incidence of cervical cancer compared to non-Indigenous women. Despite an organised cervical screening program introduced 25 years ago, a paucity of Indigenous-identified data in Pap Smear Registers remains. Prevalence of cervical abnormalities detected among the screened Indigenous population has not previously been reported. We conducted a retrospective cohort study of population-based linked health records for 1,334,795 female Queensland residents aged 20-69 years who had one or more Pap smears during 2000-2011; from linked hospital records 23,483 were identified as Indigenous. Prevalence was calculated separately for Indigenous and non-Indigenous women, for cytology-detected low-grade (cLGA) and high-grade abnormalities (cHGA), and histologically confirmed high-grade abnormalities (hHGA). Odds ratios (OR) were estimated from logistic regression analysis. In 2010-2011 the prevalence of hHGA among Indigenous women (16.6 per 1000 women screened, 95% confidence interval [CI] 14.6-18.9) was twice that of non-Indigenous women (7.5 per 1000 women screened, CI 7.3-7.7). Adjusted for age, area-level disadvantage and place of residence, Indigenous women had higher prevalence of cLGA (OR 1.4, CI 1.3-1.4), cHGA (OR 2.2, CI 2.1-2.3) and hHGA (OR 2.0, CI 1.9-2.1). Our findings show that Indigenous women recorded on the Pap Smear Register have much higher prevalence for cLGA, cHGA and hHGA compared to non-Indigenous women. The renewed cervical screening program, to be implemented in 2017, offers opportunities to reduce the burden of abnormalities and invasive cancer among Indigenous women and address long-standing data deficiencies.

Home-based HPV self-sampling improves participation by never-screened and under-screened women: Results from a large randomized trial (iPap) in Australia.

We conducted a randomized controlled trial to determine whether HPV self-sampling increases participation in cervical screening by never- and under-screened (not screened in past 5 years) women when compared with a reminder letter for a Pap test. Never- or under-screened Victorian women aged 30-69 years, not pregnant and with no prior hysterectomy were eligible. Within each stratum (never-screened and under-screened), we randomly allocated 7,140 women to self-sampling and 1,020 to Pap test reminders. The self-sampling kit comprised a nylon tipped flocked swab enclosed in a dry plastic tube. The primary outcome was participation, as indicated by returning a swab or undergoing a Pap test; the secondary outcome, for women in the self-sampling arm with a positive HPV test, was undergoing appropriate clinical investigation. The Roche Cobas® 4800 test was used to measure presence of HPV DNA. Participation was higher for the self-sampling arm: 20.3 versus 6.0% for never-screened women (absolute difference 14.4%, 95% CI: 12.6-16.1%, p < 0.001) and 11.5 versus 6.4% for under-screened women (difference 5.1%, 95% CI: 3.4-6.8%, p < 0.001). Of the 1,649 women who returned a swab, 45 (2.7%) were positive for HPV16/18 and 95 (5.8%) were positive for other high-risk HPV types. Within 6 months, 28 (62.2%) women positive for HPV16/18 had colposcopy as recommended and nine (20%) had cytology only. Of women positive for other high-risk HPV types, 78 (82.1%) had a Pap test as recommended. HPV self-sampling improves participation in cervical screening for never- and under-screened women and most women with HPV detected have appropriate clinical investigation.

Women's experience with home-based self-sampling for human papillomavirus testing.

BACKGROUND: Increasing cervical screening coverage by reaching inadequately screened groups is essential for improving the effectiveness of cervical screening programs. Offering HPV self-sampling to women who are never or under-screened can improve screening participation, however participation varies widely between settings. Information on women's experience with self-sampling and preferences for future self-sampling screening is essential for programs to optimize participation. METHODS: The survey was conducted as part of a larger trial ("iPap") investigating the effect of HPV self-sampling on participation of never and under-screened women in Victoria, Australia. Questionnaires were mailed to a) most women who participated in the self-sampling to document their experience with and preference for self-sampling in future, and b) a sample of the women who did not participate asking reasons for non-participation and suggestions for enabling participation. Reasons for not having a previous Pap test were also explored. RESULTS: About half the women who collected a self sample for the iPap trial returned the subsequent questionnaire (746/1521). Common reasons for not having cervical screening were that having Pap test performed by a doctor was embarrassing (18 %), not having the time (14 %), or that a Pap test was painful and uncomfortable (11 %). Most (94 %) found the home-based self-sampling less embarrassing, less uncomfortable (90 %) and more convenient (98%) compared with their last Pap test experience (if they had one); however, many were unsure about the test accuracy (57 %). Women who self-sampled thought the instructions were clear (98 %), it was easy to use the swab (95 %), and were generally confident that they did the test correctly (81 %). Most preferred to take the self-sample at home in the future (88 %) because it was simple and did not require a doctor's appointment. Few women (126/1946, 7 %) who did not return a self-sample in the iPap trial returned the questionnaire. Their main reason for not screening was having had a hysterectomy. CONCLUSIONS: Home-based self-sampling can overcome emotional and practical barriers to Pap test and increase participation in cervical screening despite some women's concerns about test accuracy. Mailing to eligible women and assuring women about test accuracy could further optimize participation in screening.

A pilot study to compare dry cervical sample collection with standard practice of wet cervical samples for human papillomavirus testing.

BACKGROUND: For human papillomavirus (HPV) DNA detection, specimen collection and transportation using a dry swab without transport medium has advantages, in various situations, over liquid media. OBJECTIVE: In this pilot study we evaluated whether a dry cervical sample taken with a flocked swab (dry sample) is a valid alternative for HPV DNA testing compared with the standard practice of a wet sample taken with a cyto-broom placed directly into liquid media (wet sample). STUDY DESIGN: Women attending the dysplasia clinic at the Royal Women's Hospital, Melbourne Australia between November 2013 and February 2014 were enrolled. During colposcopic examination, a practitioner collected wet and dry cervical samples, with the order of collection randomised. In the laboratory both samples were left for a week before being tested for 14 high-risk HPV types using the Roche Cobas 4800 test. RESULTS: Overall, 209 had valid HPV results from both samples. The observed agreement for HPV detection between wet and dry samples was 92.8% and kappa was 0.85 (95% confidence interval (95% CI): 0.78-0.92). There was no statistical difference in the percent HPV positive for each sample (p = 0.30). HPV testing of the dry sample had an 88.5% (95% CI: 79.9-94.3%) sensitivity for HPV detected using the wet specimen. For the HPV results categorized hierarchically, there was 92.8% overall agreement and a kappa of 0.87 (95% CI = 0.80-0.93) for the paired results. CONCLUSION: Using dry flocked swabs to collect cervical cells is a valid alternative to collecting wet samples for HPV DNA testing using a PCR based test.

Women's views on human papillomavirus self-sampling: focus groups to assess acceptability, invitation letters and a test kit in the Australian setting.

UNLABELLED: Background The study evaluated acceptability, invitation letters and the test kit for a trial of human papillomavirus (HPV) self-sampling among never- and under-screened women in Australia. METHODS: Victorian women, 30-69 years, who had never had a Pap test or were overdue for one, participated. Four focus groups including eight to nine participants segmented by age (30-49 and 50-69 years) and screening history (never- and under-screened) were conducted in August 2013. Discussions were recorded and transcribed verbatim and data analysed using thematic content analysis. RESULTS: The response to the concept of HPV self-sampling was positive. Decision-making was largely influenced by the content of a pre-invitation letter. Appealing features of self-sampling were cost (free), convenience (home-based) and anticipated less discomfort (with a swab) than a Pap test. Small kits that fit in mailboxes were preferred over post office parcel collection. The perceived barriers include concerns about test accuracy and lack of confidence that a home-based test would give the same results as a physician administered test. Women wanted information on the timing of receipt of the results and information about the organisation providing the test. CONCLUSION: HPV self-sampling is a possible alternative for Australian women who are reluctant to have a Pap test and may increase the likelihood of participation in cervical cancer screening if women's concerns about it can be addressed. The findings of this study are relevant for researchers, policymakers and practitioners implementing self-sampling for under-screened women as part of cervical screening programs.

Assessing genital human papillomavirus genoprevalence in young Australian women following the introduction of a national vaccination program.

OBJECTIVES: Following the implementation of Australia's National HPV Vaccination Program in April 2007, this study evaluated the prevalence of vaccine-targeted human papillomavirus (HPV) genotypes (HPV 6, 11, 16, 18) amongst vaccine-eligible young women. METHODS: Between September 2011 and August 2013, women from Victoria, Australia aged 18-25 were recruited through targeted advertising on the social networking website Facebook. Participants completed an online questionnaire, and sexually active women were asked to provide a self-collected vaginal swab for HPV deoxyribonucleic acid (DNA) detection and genotyping. Samples positive for HPV were genotyped using the Linear Array HPV genotyping test (Roche Diagnostics). Self-reported HPV vaccination details were verified with the National HPV Vaccination Program Register (NHVPR). RESULTS: Of 431 vaginal swabs, 24.8% were positive for HPV DNA. Vaccine-targeted HPV genotypes were detected in only seven (1.6%) samples; all HPV 16 (of the six HPV 16 positive vaccinated women, all had received the vaccine after sexual debut). There were no cases of HPV 6, 11 or 18 identified. HPV types 51, 59, 73, 84, and 89 were the most prevalent genotypes. Vaccination rates were high, with 77.3% of participants having received all three doses of the vaccine, and there was an 89.8% concordance between self-reported and registry-reported HPV vaccination status. Strong associations were observed between vaccination status, age, language spoken at home and country of birth, as well as between HPV detection and the number of male sexual partners. CONCLUSION: Preliminary data from this study demonstrate a very low prevalence of vaccine-related HPV genotypes amongst vaccine-eligible women from Victoria, Australia. We were able to use Facebook to effectively reach and recruit young women to participate in the assessment of the impact of Australia's HPV vaccination program.

Cervical screening rates for women vaccinated against human papillomavirus.

OBJECTIVE: To compare cervical screening rates for women vaccinated with a quadrivalent human papillomavirus (HPV) vaccine with those for unvaccinated women, to address concerns that vaccinated women may not be participating in cervical screening. DESIGN, SETTING AND PARTICIPANTS: Cross-sectional analysis of linked data from the Victorian Cervical Cytology Registry and the National HPV Vaccination Program Register for 20-29-year-old women in Victoria, Australia, for the period 1 January 2009 to 31 December 2011. MAIN OUTCOME MEASURES: Screening participation rates for vaccinated and unvaccinated women. RESULTS: Participation in cervical screening during the 2-year period 2010-2011 was significantly lower in 20-24-year-old vaccinated women compared with unvaccinated women of the same age (37.6% v 47.7%, a 10.1 percentage point difference [95% CI, 9.7-10.6]; P < 0.001) and significantly lower in 25-29-year-old vaccinated women compared with unvaccinated women of the same age (45.2% v 58.7%, a 13.5 percentage point difference [95% CI, 13.1%-13.9%]; P < 0.001). Similar results were observed for participation during the 3-year period 2009-2011. CONCLUSIONS: Despite education messages provided to young women, our results suggest that vaccinated women are being screened at lower rates than unvaccinated women in Australia. While some degree of undermatching of women in the study may have occurred, this cannot wholly explain our findings. Effective implementation of Individual Healthcare Identifiers to health records, including registry records, is needed to prevent potential undermatching of individuals in future linkage studies. In the meantime, efforts to increase participation in cervical screening by vaccinated women are needed.

Rationale and design of the iPap trial: a randomized controlled trial of home-based HPV self-sampling for improving participation in cervical screening by never- and under-screened women in Australia.

BACKGROUND: Organized screening based on Pap tests has substantially reduced deaths from cervical cancer in many countries, including Australia. However, the impact of the program depends upon the degree to which women participate. A new method of screening, testing for human papillomavirus (HPV) DNA to detect the virus that causes cervical cancer, has recently become available. Because women can collect their own samples for this test at home, it has the potential to overcome some of the barriers to Pap tests. The iPap trial will evaluate whether mailing an HPV self-sampling kit increases participation by never- and under-screened women within a cervical screening program. METHODS/DESIGN: The iPap trial is a parallel randomized controlled, open label, trial. Participants will be Victorian women age 30-69 years, for whom there is either no record on the Victorian Cervical Cytology Registry (VCCR) of a Pap test (never-screened) or the last recorded Pap test was between five to fifteen years ago (under-screened). Enrolment information from the Victorian Electoral Commission will be linked to the VCCR to determine the never-screened women. Variables that will be used for record linkage include full name, address and date of birth. Never- and under-screened women will be randomly allocated to either receive an invitation letter with an HPV self-sampling kit or a reminder letter to attend for a Pap test, which is standard practice for women overdue for a test in Victoria. All resources have been focus group tested. The primary outcome will be the proportion of women who participate, by returning an HPV self-sampling kit for women in the self-sampling arm, and notification of a Pap test result to the Registry for women in the Pap test arm at 3 and 6 months after mailout. The most important secondary outcome is the proportion of test-positive women who undergo further investigations at 6 and 12 months after mailout of results. DISCUSSION: The iPap trial will provide strong evidence about whether HPV self-sampling could be used in Australia to improve participation in cervical screening for never-and under-screened women. TRIAL REGISTRATION: ANZCTR Identifier: ACTRN12613001104741; UTN: U1111-1148-3885.

High-grade cervical abnormalities and cervical cancer in women following a negative Pap smear with and without an endocervical component: a cohort study with 10 years of follow-up.

The proportion of Pap smears containing an endocervical component (ECC) has been declining in Australia. Given that ECC negative (ECC-) smears may be associated with reduced sensitivity, we undertook a retrospective cohort study to estimate rates of histologically confirmed high-grade cervical abnormality (HGA) and cancer in women with negative Pap smears with and without an ECC. Women 18-69 years with at least two Pap smears between 1 January 2001 and 31 December 2010 with the first smear in that period (index smear) showing no abnormality were eligible. Follow-up ended at date of the first abnormal smear, date of histological diagnosis, date of hysterectomy, date of death, or 31 December 2010, whichever came first. ECC status was treated as a time varying exposure. Follow-up was split at each smear after the index smear. Poisson regression was used to estimate adjusted incidence rates and incidence rate ratios (IRR) by ECC status. The incidence rate of histologically confirmed HGA was significantly lower following ECC- smears than after ECC+ smears (adjusted IRR: 0.69, 95%Confidence Interval (CI) 0.62-0.77), particularly at older ages (interaction between ECC status and age, p = 0.001). In contrast, the overall rate of invasive cancer was not significantly different after ECC- than after ECC+ smears (IRR: 1.27, 95%CI 0.90-1.77). In conclusion, women had a lower rate of confirmed HGA and no significant increase in the rate of invasive cervical cancer following ECC- smears. This study does not support differential (accelerated) follow-up in women with a negative smear without an endocervical component.

The time-evolution of DCIS size distributions with applications to breast cancer growth and progression.

Ductal carcinoma in situ (DCIS) lesions are non-invasive tumours of the breast that are thought to precede most invasive breast cancers (IBCs). As individual DCIS lesions are initiated, grow and invade (i.e. become IBC), the size distribution of the DCIS lesions present in a given human population will evolve. We derive a differential equation governing this evolution and show, for given assumptions about growth and invasion, that there is a unique distribution which does not vary with time. Further, we show that any initial distribution converges to this stationary distribution exponentially quickly. Therefore, it is reasonable to assume that the stationary distribution governs the size of DCIS lesions in human populations which are relatively stable with respect to the determinants of breast cancer. Based on this assumption and the size data of 110 DCIS lesions detected in a mammographic screening programme between 1993 and 2000, we produce maximum likelihood estimates for certain growth and invasion parameters. Assuming that DCIS size is proportional to a positive power p of the time since tumour initiation, we estimate p to be 0.50 with a 95% confidence interval of (0.35, 0.71). Therefore, we estimate that DCIS lesions follow a square-root growth law and hence that they grow rapidly when small and relatively slowly when large. Our approach and results should be useful for other mathematical studies of cancer, especially those investigating biological mechanisms of invasion.

Impact of a population-based HPV vaccination program on cervical abnormalities: a data linkage study.

BACKGROUND: Australia was one of the first countries to introduce a publicly funded national human papillomavirus (HPV) vaccination program that commenced in April 2007, using the quadrivalent HPV vaccine targeting 12- to 13-year-old girls on an ongoing basis. Two-year catch-up programs were offered to 14- to 17- year-old girls in schools and 18- to 26-year-old women in community-based settings. We present data from the school-based program on population-level vaccine effectiveness against cervical abnormalities in Victoria, Australia. METHODS: Data for women age-eligible for the HPV vaccination program were linked between the Victorian Cervical Cytology Registry and the National HPV Vaccination Program Register to create a cohort of screening women who were either vaccinated or unvaccinated. Entry into the cohort was 1 April 2007 or at first Pap test for women not already screening. Vaccine effectiveness (VE) and hazard ratios (HR) for cervical abnormalities by vaccination status between 1 April 2007 and 31 December 2011 were calculated using proportional hazards regression. RESULTS: The study included 14,085 unvaccinated and 24,871 vaccinated women attending screening who were eligible for vaccination at school, 85.0% of whom had received three doses. Detection rates of histologically confirmed high-grade (HG) cervical abnormalities and high-grade cytology (HGC) were significantly lower for vaccinated women (any dose) (HG 4.8 per 1,000 person-years, HGC 11.9 per 1,000 person-years) compared with unvaccinated women (HG 6.4 per 1,000 person-years, HGC 15.3 per 1,000 person-years) HR 0.72 (95% CI 0.58 to 0.91) and HR 0.75 (95% CI 0.65 to 0.87), respectively. The HR for low-grade (LG) cytological abnormalities was 0.76 (95% CI 0.72 to 0.80). VE adjusted a priori for age at first screening, socioeconomic status and remoteness index, for women who were completely vaccinated, was greatest for CIN3+/AIS at 47.5% (95% CI 22.7 to 64.4) and 36.4% (95% CI 9.8 to 55.1) for women who received any dose of vaccine, and was negatively associated with age. For women who received only one or two doses of vaccine, HRs for HG histology were not significantly different from 1.0, although the number of outcomes was small. CONCLUSION: A population-based HPV vaccination program in schools significantly reduced cervical abnormalities for vaccinated women within five years of implementation, with the greatest vaccine effectiveness observed for the youngest women.

Measuring effectiveness of the cervical cancer vaccine in an Australian setting (the VACCINE study).

BACKGROUND: The quadrivalent human papillomavirus vaccine has been provided in Australia through the National Human Papillomavirus Vaccination Program since April 2007. National registry data demonstrates good coverage of the vaccine, with 73% of school-aged girls having received all three doses. To evaluate the effectiveness of the program, we propose a two-pronged approach. In one (sub study A), the prevalence of the vaccine-targeted human papillomavirus genotypes in a population cohort is being estimated, and will be analysed in relation to vaccination status, cervical cytology screening status, demographic, social, behavioural, medical and clinical factors. In sub study B, the distribution of human papillomavirus genotypes detected in high grade cervical intraepithelial neoplastic lesions from vaccine eligible women is being assessed. METHODS/DESIGN: Sub Study A involves the recruitment of 1569 women aged 18-25, residing in Victoria, Australia, through Facebook advertising. Women who are sexually active are being asked to provide a self-collected vaginal swab, collected at home and posted into the study centre, where human papillomavirus DNA detection and genotyping is performed. Participants also complete an online questionnaire regarding sexual history, experience with, knowledge of, and attitudes towards human papillomavirus, the human papillomavirus vaccine, and cervical screening.Sub Study B will involve the collection of 500 cervical biopsies, positively identified as containing high grade cervical intraepithelial neoplastic lesions and/or adenocarcinoma in situ. Five serial sections are being taken from each case: sections 1 and 5 are being assessed to confirm the presence of the high grade cervical intraepithelial neoplastic lesions or adenocarcinoma in situ; human papillomavirus genotyping is performed on sections 2 and 3; single lesions are excised from section 4 using laser capture microdissection to specifically define causality of a human papillomavirus genotyping of each specific lesion. DISCUSSION: Australia is well placed to gain a clear and early insight into the effectiveness of the human papillomavirus vaccine in reducing the prevalence of human papillomavirus infection in young women, and any subsequent reduction in the prevalence of pre-cancerous cervical lesions, specifically high grade cervical intraepithelial neoplasia lesions, particularly of vaccine related types. The findings of a successful population based human papillomavirus program will have wide-reaching translational benefits across the globe.

Bodyweight and other correlates of symptom-detected breast cancers in a population offered screening.

OBJECTIVE: To determine the factors associated with symptom-detected breast cancers in a population offered screening. METHODS: We interviewed 1,459 Australian women aged 40-69, 946 with symptom-detected and 513 with mammogram-detected invasive breast cancers ≥ 1.1 cm in diameter about their personal, mammogram, and breast histories before diagnosis and reviewed medical records for tumor characteristics and mammogram dates, calculating ORs and 95% confidence intervals (CIs) for symptom- versus mammogram-detected cancers in logistic regression models. RESULTS: Lack of regular mammograms (<2 mammograms in the 4.5 years before diagnosis) was the strongest correlate of symptom-detected breast cancer (OR = 3.04 for irregular or no mammograms). In women who had regular mammograms (≥ 2 mammograms in the 4.5 years before diagnosis), the independent correlates of symptom-detected cancers were low BMI (OR < 25 kg/m(2) vs. ≥ 30 kg/m(2) = 2.18, 95% CI 1.23-3.84; p = 0.008), increased breast density (available in 498 women) (OR highest quarter vs. lowest = 3.50, 95% CI 1.76-6.97; p (trend) = 0.004), high-grade cancer, and a larger cancer (each p < 0.01). In women who did not have regular mammograms, the independent correlates were age <50 years, a first cancer, and a ≥ 2-cm cancer. Smoking appeared to modify the association of symptom-detected cancer with low BMI (higher ORs for low BMI in current smokers) and estrogen receptor (ER) status (higher ORs for low BMI in ER cancers). CONCLUSION: Women with low BMI may benefit from a tailored approach to breast cancer detection, particularly if they smoke.

Primary prophylactic human papillomavirus vaccination programs: future perspective on global impact.

Of the 40 types of human papillomavirus that can infect the mucosal epithelium, four types can now be prevented using prophylactic vaccination. Two of these types (high-risk types 16 and 18) cause 70% of cervical cancers, a proportion of other genital cancers and a subset of head and neck cancers. The low-risk types 6 and 11 cause 90% of genital warts and the disease recurrent respiratory papillomatosis. Thus, if primary HPV vaccination programs can be implemented effectively, the potential for a reduction in global disease burden is great. This article considers the current issues and challenges in delivering primary HPV vaccination programs effectively and the likely impact of the vaccines in both the near and more distant future.

Early effect of the HPV vaccination programme on cervical abnormalities in Victoria, Australia: an ecological study.

BACKGROUND: Australia introduced a human papillomavirus (HPV) vaccination programme with the quadrivalent HPV vaccine for all women aged 12-26 years between 2007 and 2009. We analysed trends in cervical abnormalities in women in Victoria, Australia, before and after introduction of the vaccination programme. METHODS: With data from the Victorian Cervical Cytology Registry between 2003 and 2009, we compared the incidence of histopathologically defined high-grade cervical abnormalities (HGAs, lesions coded as cervical intraepithelial neoplasia of grade 2 or worse or adenocarcinoma in situ; primary outcome) and low-grade cytological abnormalities (LGAs) in five age groups before (Jan 1, 2003, to March 31, 2007) and after (April 1, 2007, to Dec 31, 2009) the vaccination programme began. Binary comparisons between the two periods were done with Fisher's exact test. Poisson piecewise regression analysis was used to compare incident rate trends. FINDINGS: After the introduction of the vaccination programme, we recorded a decrease in the incidence of HGAs by 0·38% (95% CI 0·61-0·16) in girls younger than 18 years. This decrease was progressive and significantly different to the linear trend in incidence before introduction of the vaccination (incident rate ratio 1·14, 1·00-1·30, p=0·05). No similar temporal decline was recorded for LGAs or in older age groups. INTERPRETATION: This is the first report of a decrease in incidence of HGAs within 3 years after the implementation of a population-wide HPV vaccination programme. Linkage between vaccination and screening registers is needed to confirm that this ecological observation is attributable to vaccination and to monitor participation in screening among vaccinated women. FUNDING: None.

Measuring human papillomavirus (HPV) vaccination coverage and the role of the National HPV Vaccination Program Register, Australia.

Accurate estimates of HPV vaccination coverage are critical for determining the proportion of the target female population that is not protected by the vaccine, as well as for monitoring the performance of vaccine delivery programs. The implementation of an HPV vaccination register, either as part of an existing immunisation register or stand-alone, can add substantial benefits to an HPV vaccination program. In Australia, the National HPV Vaccination Program Register supports the HPV vaccination program by providing information to consumers and providers about incomplete courses as well as estimates of vaccination coverage by age and area. Future monitoring of vaccine effectiveness will be facilitated by cross-linking to Pap test registries.