Simultaneously characterizing the comparative economics of routine female adolescent nonavalent human papillomavirus (HPV) vaccination and assortativity of sexual mixing in Hong Kong Chinese: a modeling analysis

Projected Time for the Elimination of Cervical Cancer Under Various Intervention Scenarios: Age-Period-Cohort Macrosimulation Study

BACKGROUND

The World Health Organization aims for the global elimination of cervical cancer, necessitating modeling studies to forecast long-term outcomes.

OBJECTIVE

This paper introduces a macrosimulation framework using age-period-cohort modeling and population attributable fractions to predict the timeline for eliminating cervical cancer in Taiwan.

METHODS

Data for cervical cancer cases from 1997 to 2016 were obtained from the Taiwan Cancer Registry. Future incidence rates under the current approach and various intervention strategies, such as scaled-up screening (cytology based or human papillomavirus [HPV] based) and HPV vaccination, were projected.

RESULTS

Our projections indicate that Taiwan could eliminate cervical cancer by 2050 with either 70% compliance in cytology-based or HPV-based screening or 90% HPV vaccination coverage. The years projected for elimination are 2047 and 2035 for cytology-based and HPV-based screening, respectively; 2050 for vaccination alone; and 2038 and 2033 for combined screening and vaccination approaches.

CONCLUSIONS

The age-period-cohort macrosimulation framework offers a valuable policy analysis tool for cervical cancer control. Our findings can inform strategies in other high-incidence countries, serving as a benchmark for global efforts to eliminate the disease.

Modeling the Health Impact and Cost-Effectiveness of a Combined Schoolgirl HPV Vaccination and Cervical Cancer Screening Program in Guangdong Province, China

Low human papillomavirus (HPV) vaccine uptake is a key barrier to cervical cancer elimination. We aimed to evaluate the health impact and cost-effectiveness of introducing different HPV vaccines into immunization programs and scaling up the screening program in Guangdong. We used a dynamic compartmental model to estimate the impact of intervention strategies during 2023-2100. We implemented the incremental cost-effectiveness ratio (ICER) in costs per averted disability-adjusted life year (DALY) as an indicator to assess the effectiveness of the intervention. We used an age-standardized incidence of 4 cases per 100,000 women as the threshold for the elimination of cervical cancer. Compared with the status quo, scaling up cervical cancer screening coverage alone would prevent 215,000 (95% CI: 205,000 to 227,000) cervical cancer cases and 49,000 (95% CI: 48,000 to 52,000) deaths during 2023-2100. If the coverage of vaccination reached 90%, domestic two-dose 2vHPV vaccination would be more cost-effective than single-dose and two-dose 9vHPV vaccination. If Guangdong introduced domestic two-dose 2vHPV vaccination at 90% coverage for schoolgirls from 2023 and increased the screening coverage, cervical cancer would be eliminated by 2049 (95% CI 2047 to 2051). Introducing two doses of domestic 2vHPV vaccination for schoolgirls and expanding cervical cancer screening is estimated to be highly cost-effective to accelerate the elimination of cervical cancer in Guangdong.

Public health impact of 2-, 4-, and 9-valent HPV vaccination in females on cervical and noncervical diseases in men and women under different coverage scenarios in China: A simulation study

The high prevalence of human papillomavirus (HPV) infection in China suggests there would be a substantial positive health impact of widespread vaccination against HPV. We adapted a previously described dynamic transmission model of the natural history of HPV infection and related diseases to the Chinese setting to estimate the public health impact in China of 2-valent (with and without cross-protection), 4-valent, and 9-valent HPV vaccination strategies. The model predicted the incidence and mortality associated with HPV-related diseases, including cervical and noncervical cancers, genital warts, and recurrent respiratory papillomatosis (RRP), based on the various vaccination coverage rate (VCR) scenarios, over a 100-year time horizon. The public health impact of the 4 vaccination strategies was estimated in terms of cases and deaths averted compared to a scenario with no vaccination. Under the assumption of various primary and catch-up VCR scenarios, all 4 vaccination strategies reduced the incidence of cervical cancer in females and noncervical cancers in both sexes, and the 4-valent and 9-valent vaccines reduced the incidence of genital warts and RRP in both sexes. The 9-valent vaccination strategy was superior on all outcomes. The number of cervical cancer cases averted over 100 years ranged from ~ 1 million to ~ 5 million while the number of cervical cancer deaths averted was ~ 345,000 to ~ 1.9 million cases, depending on the VCR scenario. The VCR for primary vaccination was the major driver of cases averted.

Accounting for Adverse Events Following Immunization in Economic Evaluation: Systematic Review of Economic Evaluations of Pediatric Vaccines Against Pneumococcus, Rotavirus, Human Papillomavirus, Meningococcus and Measles-Mumps-Rubella-Varicella

OBJECTIVES

Economic evaluations of vaccines should accurately represent all relevant economic and health consequences of vaccination, including losses due to adverse events following immunization (AEFI). We investigated to what extent economic evaluations of pediatric vaccines account for AEFI, which methods are used to do so and whether inclusion of AEFI is associated with study characteristics and the vaccine's safety profile.

METHODS

A systematic literature search (MEDLINE, EMBASE, Cochrane Systematic Reviews and Trials, Database of the Centre for Reviews and Dissemination of the University of York, EconPapers, Paediatric Economic Database Evaluation, Tufts New England Cost-Effectiveness Analysis Registry, Tufts New England Global Health CEA, International Network of Agencies for Health Technology Assessment Database) was performed for economic evaluations published between 2014 and 29 April 2021 (date of search) pertaining to the five groups of pediatric vaccines licensed in Europe and the United States since 1998: the human papillomavirus (HPV) vaccines, the meningococcal vaccines (MCV), the measles-mumps-rubella-varicella (MMRV) combination vaccines, the pneumococcal conjugate vaccines (PCV) and the rotavirus vaccines (RV). Rates of accounting for AEFI were calculated, stratified by study characteristics (e.g., region, publication year, journal impact factor, level of industry involvement) and triangulated with the vaccine's safety profile (Advisory Committee on Immunization Practices [ACIP] recommendations and information on safety-related product label changes). The studies accounting for AEFI were analyzed in terms of the methods used to account for both cost and effect implications of AEFI.

RESULTS

We identified 112 economic evaluations, of which 28 (25%) accounted for AEFI. This proportion was significantly higher for MMRV (80%, four out of five evaluations), MCV (61%, 11 out of 18 evaluations) and RV (60%, nine out of 15 evaluations) compared to HPV (6%, three out of 53 evaluations) and PCV (5%, one out of 21 evaluations). No other study characteristics were associated with a study's likelihood of accounting for AEFI. Vaccines for which AEFI were more frequently accounted for also had a higher frequency of label changes and a higher level of attention to AEFI in ACIP recommendations. Nine studies accounted for both the cost and health implications of AEFI, 18 studies considered only costs and one only health outcomes. While the cost impact was usually estimated based on routine billing data, the adverse health impact of AEFI was usually estimated based on assumptions.

DISCUSSION

Although (mild) AEFI were demonstrated for all five studied vaccines, only a quarter of reviewed studies accounted for these, mostly in an incomplete and inaccurate manner. We provide guidance on which methods to use to better quantify the impact of AEFI on both costs and health outcomes. Policymakers should be aware that the impact of AEFI on cost-effectiveness is likely to be underestimated in the majority of economic evaluations.

Maximizing the cost-effectiveness of cervical screening in the context of routine HPV vaccination by optimizing screening strategies with respect to vaccine uptake: a modeling analysis

BACKGROUND

Regarding primary and secondary cervical cancer prevention, the World Health Organization proposed the cervical cancer elimination strategy that requires countries to achieve 90% uptake of human papillomavirus (HPV) vaccines and 70% screening uptake. The optimal cervical screening strategy is likely different for unvaccinated and vaccinated cohorts upon national HPV immunization. However, health authorities typically only provide a one-size-fits-all recommendation for the general population. We aimed to evaluate the cost-effectiveness for determining the optimal screening strategies for vaccinated and unvaccinated cohorts.

METHODS

We considered the women population in Hong Kong which has a unique HPV infection and cervical cancer epidemiology compared to other regions in China and Asia. We used mathematical models which comprise a deterministic age-structured compartmental dynamic component and a stochastic individual-based cohort component to evaluate the cost-effectiveness of screening strategies for cervical screening. Following the recommendations in local guidelines in Hong Kong, we considered strategies that involved cytology, HPV testing, or co-testing as primary cervical screening. We also explored the impacts of adopting alternative de-intensified strategies for vaccinated cohorts. The 3-year cytology screening was used as the base comparator while no screening was also considered for vaccinated cohorts. Women's lifetime life years, quality-adjusted life years, and costs of screening and treatment were estimated from the societal perspective based on the year 2022 and were discounted by 3% annually. Incremental cost-effectiveness ratios (ICERs) were compared to a willingness to pay (WTP) threshold of one gross domestic product per capita (US $47,792). Probabilistic and one-way sensitivity analyses were conducted.

RESULTS

Among unvaccinated cohorts, the strategy that adds reflex HPV to triage mild cytology abnormality generated more life years saved than cytology-only screening and could be a cost-effective alternative. Among vaccinated cohorts, when vaccine uptake was 85% (based on the uptake in 2022), all guideline-based strategies (including the cytology-only screening) had ICERs above the WTP threshold when compared with no screening if the vaccine-induced protection duration was 20 years or longer. Under the same conditions, HPV testing with genotyping triage had ICERs (compared with no screening) below the WTP threshold if the routine screening interval was lengthened to 10 and 15 years or screening was initiated at ages 30 and 35 years.

CONCLUSIONS

HPV testing is a cost-effective alternative to cytology for vaccinated cohorts, and the associated optimal screening frequency depends on vaccine uptake. Health authorities should optimize screening recommendations by accounting for population vaccine uptake.

Cost-Benefit Analysis of Human Papillomavirus Vaccine in Iran

Despite increasing global attention to the national human papillomavirus (HPV) immunization program, this program is controversial in Iran. Evidence indicates that HPV vaccination is not cost-effective in Iran. Using cost-effectiveness analysis for decision-making about public health interventions such as vaccination is controversial because its potential benefits may not fit this framework. This study aimed to evaluate the economic effects of the HPV vaccination by cost-benefit analysis (CBA) using bivalent and quadrivalent in Iran in 2020. We performed a CBA from a societal perspective. We used two approaches of the vaccine's economic benefits: willingness to pay by discrete choice experiment and cost of illness. Costs only included the vaccine cost. The cost of two doses of bivalent and quadrivalent vaccines were US $29 and the US $151, respectively (US $1 = IRR 42,000). The benefits of bivalent and quadrivalent vaccines were US $ - 432, US $380 per person using the willingness to pay approach, and they were US $7375 and US $6590 thorough cost-of-illness approach. The cost-benefit ratio (CBR) of bivalent and quadrivalent vaccines was - 15.11 and 2.51 by the willingness to pay approach, and 258.12 and 43.51 by the cost of illness approach. This study confirms the benefits of the national bivalent and quadrivalent vaccination programs and provides reliable evidence for policy-makers programming HPV vaccination.

Status and epidemiological characteristics of high-risk human papillomavirus infection in multiple centers in Shenyang

The different human papillomavirus (HPV) strains cause warts in various regions of the body. However, considering that the status and genotype distribution of HPV infection in women in Shenyang remain unknown, herein, we investigated the epidemiological characteristics of high-risk HPV (HR-HPV) infection in women in Shenyang, as well as the current state of HPV infection in Shenyang, to provide a theoretical basis for the prevention and treatment of cervical cancer. From December 2018 to December 2021, 6,432 urban and rural women from the Liaoning Cancer Hospital and the Sujiatun Women and Infants’ Hospital were assessed via the Thinprep cytology test (TCT) and HR-HPV detection. Of the 5,961 women enrolled, 739 were HPV positive (12.40%) and 562 were TCT positive (9.43%). Statistical analyses identified the following HPV risk factors: high school education or lower [OR = 1.426 (1.199–1.696), p < 0.001], age at first sexual encounter ≤ 19 years [OR = 1.496 (1.008–2.220), p = 0.046], and number of sexual partners > 1 [OR = 1.382 (1.081–1.768), p = 0.010], atypical squamous cells of undetermined significance (ASCUS) and above [OR = 10.788 (8.912–13.060), p < 0.001], non-condom-based contraception [OR = 1.437 (1.103–1.871), p = 0.007], nationalities other than Han [OR = 1.690 (1.187–2.406), p = 0.004], rural residence [OR = 1.210 (1.031–1.419), p = 0.020]. Compared to the HPV infection rate of women aged 56–65, that in women aged 35–45 [OR = 0.687 (0.549–0.860), p = 0.001] and 46–55 [OR = 0.740 (0.622–0.879), p = 0.001] decreased significantly. To conclude, risk factors of HPV infection among female patients include high school age and below, initial sexual encounter at age ≤ 19 years, number of sexual partners > 1, ASCUS and above, non-condom contraception, nationalities other than Han nationality and rural population. Collectively, this study provides insights for the improved prevention and treatment of cervical cancer.

Cost-effectiveness of human papillomavirus vaccine in China: a systematic review of modelling studies

OBJECTIVES

China suffers from high burdens of human papillomavirus (HPV) and cervical cancer, whereas the uptake of HPV vaccine remains low. The first Chinese domestic HPV vaccine was released in 2019. However, collective evidence on cost-effectiveness of HPV vaccination in China has yet to be established. We summarised evidence on the cost-effectiveness of HPV vaccine in China.

DESIGN

Systematic review and narrative synthesis DATA SOURCES: PubMed, EMBASE, China National Knowledge Infrastructure and Wanfang Data were searched through 2 January 2021 ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Cost-effectiveness studies using a modelling approach focusing on HPV vaccination interventions in the setting of China were included for review.

DATA EXTRACTION AND SYNTHESIS

We extracted information from the selected studies focusing on cost-effectiveness results of various vaccination programmes, key contextual and methodological factors influencing cost-effectiveness estimates and an assessment of study quality.

RESULTS

A total of 14 studies were included for review. Considerable heterogeneity was found in terms of the methodologies used, HPV vaccination strategies evaluated and study quality. The reviewed studies generally supported the cost-effectiveness of HPV vaccine in China, although some reached alternative conclusions, particularly when assessed incremental to cervical cancer screening. Cost of vaccination was consistently identified as a key determinant for the cost-effectiveness of HPV vaccination programmes.

CONCLUSIONS

Implementing HPV vaccination programmes should be complemented with expanded cervical cancer screening, while the release of lower-priced domestic vaccine offers more promising potential for initiating public HPV vaccination programmes. Findings of this study contributes important evidence for policies for cervical cancer prevention in China and methodological implications for future modelling efforts.

The impact and cost-effectiveness of 9-valent human papillomavirus vaccine in adolescent females in Hong Kong

Introduction

In Hong Kong (HK), a single-cohort vaccination program for 10–12-year-old girls with the 9-valent human papillomavirus (HPV) vaccine (9vHPV; types 6/11/16/18/31/33/45/52/58) has been launched. This study assessed the public health impact and cost-effectiveness of implementing routine 9vHPV vaccination (12-year-olds) with or without catch-up 9vHPV vaccination (13–18-year-olds) in HK.

Methods

The health impact and costs of implementing routine 9vHPV vaccination with or without catch-up vaccination over a 100-year time horizon were evaluated using a validated HPV-type transmission dynamic model adapted to the HK population; analyses were performed from a healthcare payer perspective. Routine vaccination (12-year-old girls) and catch-up vaccination (13–18 years) assumed vaccine coverage rates of 70% (base case) and 30%, respectively. The model also assumed herd immunity, lifelong vaccine protection, a discount rate of 3%, and a cost per dose of HK dollars (HKD) 858 [United States dollars (USD) 110] and HKD 1390 (USD 179) for the 2-valent HPV (2vHPV) and 9vHPV vaccines, respectively. HPV disease-related incidence and the incremental cost-effectiveness ratio (ICER) per quality-adjusted-life-year (QALY) were estimated. Cost-effectiveness was determined at a ceiling threshold of HK dollars (HKD) 382,046 (USD 49,142) or 1.0 times the gross domestic product per capita of HK.

Results

Compared with routine 9vHPV alone, routine plus catch-up 9vHPV is projected to reduce cervical cancer incidence by 3.4%. Routine plus catch-up 9vHPV will also reduce genital warts incident cases for males/females by 2.6%/5.4%. The incremental cost-effectiveness ratios were HKD 29,911 (USD 3847)/quality-adjusted life-year (QALY) for routine plus catch-up 9vHPV versus routine 9vHPV alone and HKD 25,524 (USD 3283)/QALY for routine 9vHPV alone versus screening only. Sensitivity analyses indicated that routine plus catch-up 9vHPV compared with routine 9vHPV alone remained cost-effective at coverage rates of 30% and 90%.

Conclusions

This analysis predicts that the current HK vaccination strategy can be considered cost-effective and will provide maximum health benefit. These results support addition of the routine 9vHPV vaccine with or without catch-up 9vHPV vaccination to the regional vaccination program in HK.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12962-021-00328-x.

Modeling the epidemiological impact and cost-effectiveness of a combined schoolgirl HPV vaccination and cervical cancer screening program among Chinese women

Human papillomavirus (HPV) infection is common in women and also the main cause of cervical cancer. Based on a dynamic compartmental model, we aimed to evaluate the population impact and cost-effectiveness of strategies that combined cervical cancer screening and HPV schoolgirl vaccination for Chinese women. The effectiveness of interventions was assessed by comparing modeled scenarios to the status quo, where a 3-y cervical cancer screening program remained at a 20% coverage and without a universal HPV vaccination program. Our study demonstrated that increasing screening coverage from 20% to 50% would reduce the high-risk HPV (HR-HPV) prevalence to 5.4%, whereas a universal schoolgirl vaccination program using the quadrivalent vaccine (qHPV) with a coverage of 50% would reduce the prevalence to 2.9% by 2069. Scaling-up the cervical screening coverage to 50% will prevent 16,012 (95% CI: 8,791 to 25,913) Disability-Adjusted Life-Years (DALYs) per year, with an incremental cost-effectiveness ratio (ICER) of US$ 10,958 (95% CI: $169 to $26,973)/DALY prevented. At the current qHPV price, vaccinating 50% of school girls will prevent 13,854 (95% CI: 8,355 to 20,776) DALYs/year, but the corresponding incremental cost-effectiveness ratio (ICER, US$ 83,043, 95% CI: $52,234 to $138,025) exceeds cost-effectiveness threshold (i.e., 3 times GDP per-capita of China: $30,792). The qHPV vaccine requires at least a 50% price reduction to be cost-effective. Vaccinating schoolgirls will result in a large population health benefit in the long term, but such a universal HPV vaccination program can only be cost-effective with a substantial price reduction.

Cost-effectiveness analysis of the nonavalent human papillomavirus vaccine for the prevention of cervical cancer in Singapore

BACKGROUND

The nonavalent human papillomavirus (HPV) vaccine has been shown to extend protection against oncogenic HPV types 31/33/45/52/58 (HPV-OV) not covered by the bivalent and quadrivalent HPV vaccines. Besides its clinical benefit, evidence on the economic value of the nonavalent vaccine is required to inform local vaccination strategies and funding decisions. This study evaluated the cost-effectiveness of replacing the bivalent vaccine with the nonavalent vaccine in the national school-based HPV vaccination programme in Singapore.

METHODS

An existing age-structured dynamic transmission model coupled with stochastic individual-based simulations was adapted to project the health and economic impact of vaccinating 13-year-old girls with two doses of the nonavalent or bivalent HPV vaccines in Singapore. Direct costs (in Singapore dollars, S$) were obtained from public healthcare institutions in Singapore, while health state utilities were sourced from the literature. Incremental cost-effectiveness ratios (ICERs) were estimated over a lifetime horizon, from a healthcare system perspective. Probabilistic sensitivity analysis was performed to obtain the ICERs and corresponding variations across variable uncertainty. Particularly, this study tested the scenarios of lifelong and 20-year vaccine-induced protection, assumed 96.0% and 22.3% cross-protection against HPV-OV by nonavalent and bivalent vaccines respectively, and fixed vaccine prices per dose at S$188 for nonavalent and S$61.50 for bivalent vaccines.

RESULTS

Compared with the bivalent vaccine, the use of the nonavalent vaccine was associated with an ICER of S$61,629 per quality-adjusted life year gained in the base case. The result was robust across a range of plausible input values, and to assumptions regarding the duration of vaccine protection.

CONCLUSION

Given the high ICER, the nonavalent vaccine is unlikely to represent a cost-effective option compared with the bivalent vaccine for school-based HPV vaccination of 13-year old female students in Singapore. Substantial price reductions would be required to justify its inclusion in the school-based programme in the future.

Effectiveness and cost-effectiveness of eliminating cervical cancer through a tailored optimal pathway: a modeling study

BACKGROUND

The World Health Assembly has adopted a global strategy to eliminate cervical cancer. However, neither the optimal pathway nor the corresponding economic and health benefits have been evaluated. We take China as an example to assess the optimal pathway towards elimination and the cost-effectiveness of tailored actions.

METHODS

A validated hybrid model was used to assess the costs and benefits of alternative strategies combining human papillomavirus vaccination, cervical screening, and treatment of pre-invasive lesions and invasive cancer for females with different immunization history. All Chinese females living or projected to be born during 2015-2100, under projected trends in aging, urbanization, and sexual activity, were considered. Optimal strategies were determined by cost-effectiveness efficiency frontiers. Primary outcomes were cervical cancer cases and deaths averted and incremental cost-effectiveness ratios (ICERs). We employed a lifetime horizon from a societal perspective. One-way and probabilistic sensitivity analyses evaluate model uncertainty.

RESULTS

The optimal pathway represents an integration of multiple tailored strategies from females with different immunization history. If China adopts the optimal pathway, the age-standardized incidence of cervical cancer is predicted to decrease to fewer than four new cases per 100,000 women (i.e., elimination) by 2047 (95% confidence interval 2043 to 2050). Compared to the status quo, the optimal pathway would avert a total of 7,509,192 (6,922,744 to 8,359,074) cervical cancer cases and 2,529,873 (2,366,826 to 2,802,604) cervical cancer deaths in 2021-2100, with the discounted ICER being $- 339 (- 687 to - 79) per quality-adjusted life-year.

CONCLUSIONS

By adopting an optimal pathway from 2021 (namely, the year of the first Chinese Centennial Goals) onwards, cervical cancer could be eliminated by the late 2040s (namely, ahead of the second Chinese Centennial Goals) while saving net economic costs in China.

The cost-effectiveness of prostate health index for prostate cancer detection in Chinese men

BACKGROUND

Prostate-specific antigen (PSA) and prostate health index (PHI) have been used as biomarkers for prostate cancer detection. In this study, we aimed to evaluate the cost-effectiveness of PHI for prostate cancer detection in Chinese men.

METHOD

We developed a Markov model for Chinese male patient aged 50-75 years old. The PSA strategy was to offer TRUS-PB for all patients with elevated PSA of 4-10 ng/mL. The PHI strategy was to offer PHI for patients with elevated PSA of 4-10 ng/mL. TRUS-PB would only be offered for patients with PHI >35.0. Model inputs were extracted from local data when available. The cost per quality-adjusted life years gained for both strategies were calculated. The incremental cost-effectiveness ratios in relation to the willingness-to-pay (WTP) threshold were compared. One-way sensitivity analysis and probabilistic sensitivity analysis were performed. Cost-effectiveness acceptability curves were also constructed.

RESULTS

With a Markov model of 25 screening cycles from age 50 to 75 years, the mean total costs per man were estimated to be USD 27,439 in the PSA strategy and USD 22,877 in the PHI strategy. The estimated effects were estimated to be 15.70 in the PSA strategy and 16.05 in the PHI strategy. The PHI strategy was associated with an expected decrease in cost of USD 4562 and an expected gain of 0.35 QALY, resulting in an ICER of USD -13056.56. The results were shown to be robust upon one-way sensitivity analysis. Upon Monte Carlo simulation, the PHI strategy was more cost-effective for 100% of the iterations. The PHI strategy demonstrated dominance over the PSA strategy regardless of what WTP threshold we use.

CONCLUSIONS

A PHI-based screening strategy may be more cost-effective than a PSA-based strategy for prostate cancer detection in Chinese men. These results support consideration of a PHI-based approach for prostate cancer in Hong Kong.

HPV vaccination and sexual behaviour in healthcare seeking young women in Luxembourg

Introduction

Human papillomavirus (HPV) is the most common sexually transmitted infection (STI) worldwide. Despite recommendations for HPV vaccination of young women from health authorities, parental concerns were raised whether vaccination could induce unsafe sexual behaviour in young women. Therefore, the primary aim of this study was to investigate if HPV vaccination in healthcare seeking adult women in Luxembourg was associated with unsafe sexual behaviour.

Methods

Seven hundred twenty-nine women (mean age = 22.5; range 18-43 years) were recruited either at Luxembourg family planning centres or at private gynaecology practices. All participants completed a questionnaire on vaccination status and sexual behaviour. Poisson and logistic regressions were used to study the association between sexual behaviour and vaccination status (N = 538). Both models were restricted to women younger than 26 years, since the first cohort being vaccinated would be 25 years old at the time of sampling. Assortativity of sexual mixing by age was also assessed for further transmission modelling for women <30 years reporting age of last/current sexual partner (N = 649). Women older than 29 years were excluded from the assortativity analysis due to restricted sample size.

Results

In total, 386/538 (71.8%) of participants reported receiving HPV vaccine. Vaccination uptake significantly varied by nationality and was higher in Portuguese 112/142 (78.9%) and in Luxembourgish 224/313(71.6%) residents, and lower in residents of other nationalities 50/83 (60.2%) (p = 0.011). HPV vaccination was not associated with unsafe sexual behaviour such as shorter relationship duration with current or last sexual partner (odds ratio (OR) = 1.05, 95% CI [0.94-1.16]), younger age of sexual debut (OR = 1.00, 95% CI [0.88-1.14]), increased number of lifetime sexual partners (OR = 0.95, 95% CI [0.87-1.03), higher age difference with sexual partner (OR = 1.01, 95% CI [0.95-1.08]), condom use (OR = 0.97, 95% CI [0.60-1.56]), nor with other factors like smoking (OR = 0.73, 95% CI [0.47-1.15]) and nationality. HPV vaccination was only associated with younger age (OR = 0.84, 95% CI [0.75-0.94]). Relationship duration, age of sexual debut, age difference with sexual partner, smoking, age and non-Portuguese foreign nationality were predictors of number of lifetime sexual partners. Assortativity analysis revealed that young women chose sexual partners who were 2.3 years older on average.

Conclusions

Our study found no association between unsafe sexual behaviour and HPV vaccination.