Cost of Treatment and QALYs Lost Due to Genital Warts: Data for the Economic Evaluation of HPV Vaccines in the United Kingdom

Risk-benefit analysis of 9-valent HPV vaccination for adolescent boys from an individual perspective

Japan recently approved quadrivalent human papillomavirus (HPV) vaccine for males, but 9-valent vaccine is only approved for females. Given the low female vaccination rate due to a concern of adverse events in Japan, quantifying the risk and benefit of the HPV vaccination for male may help the decision making to vaccinate adolescent boys in Japan. Using quality-adjusted life years, the risk-benefit ratio for an adolescent boy to get the 9-valent HPV vaccination was calculated. The male HPV vaccination reduced the QALY gain due to head and neck cancer, anal cancer, penile cancer, genital warts and recurrent respiratory papillomatosis by 401.63, 20.38, 9.40, 28.79 and 69.13/100,000 vaccinated persons, respectively. The total risk of the vaccination was 11.85. The risk-benefit ratio for a 12-year old boy to receive the HPV vaccination series is calculated as 0.022 (the benefit-risk ratio 44.67). In the sensitivity analysis the risk-benefit ratio ranged from 0.0001 to 0.11. for all scenarios. The much larger benefit compared with the risk for the male HPV vaccination was observed from an individual perspective. The result supports the inclusion of sex-neutral HPV vaccination into the national immunization program as well as the decision making for adolescent boys to get the vaccination.

Declines in anogenital warts diagnoses since the change in 2012 to use the quadrivalent HPV vaccine in England: data to end 2017

OBJECTIVES

In 2008, a national human papillomavirus (HPV) vaccination programme for females was introduced in England using the bivalent vaccine (HPV16 and 18 only). In 2012, the programme changed to offer the quadrivalent vaccine that includes protection against the two HPV types that cause the majority of anogenital warts (AGW; HPV6 and 11). We present data reporting AGW diagnoses in sexual health clinics (SHCs) in England to the end of 2017, including diagnoses among birth cohorts offered the quadrivalent vaccine.

METHODS

Using data from all SHCs across England, we performed ecological analyses to consider rates of AGW diagnoses by age, gender and sexual orientation. We tested for trends over time of diagnoses of AGW in young females, heterosexual males, and men who have sex with men (MSM) between the ages of 15 and 24 years during both bivalent (2009 to 2013) and quadrivalent (2014 to 2017) vaccine time periods using Poisson regression.

RESULTS

Between 2014 and 2017, there was strong evidence for a decreasing trend in the rate of AGW diagnoses at SHC among females aged 15-17 years from 257.5 to 45.7 per 100 000 population (82.3% decline) and same aged heterosexual males from 59.1 to 19.1 per 100 000 population (67.7% decline). The reductions in the incidence of AGW diagnoses in MSM aged 15-17 years were less clear (decreased by 13.6% between 2014 and 2017, from 129.9 to 112.2 per 100 000 population).

CONCLUSIONS

The moderate, unexpected declines in AGW seen since the introduction of a high-coverage HPV vaccination programme using the bivalent vaccine are being followed, as expected, by much larger declines among females offered the quadrivalent vaccine and same-aged heterosexual males. Surveillance plans are in place to continue to monitor AGW diagnoses to evaluate the impact of both female and targeted MSM HPV vaccination on early disease outcomes.

Systematic review and evidence synthesis of non-cervical human papillomavirus-related disease health system costs and quality of life estimates

BACKGROUND

Many economic evaluations of human papillomavirus vaccination should ideally consider multiple disease outcomes, including anogenital warts, respiratory papillomatosis and non-cervical cancers (eg, anal, oropharyngeal, penile, vulvar and vaginal cancers). However, published economic evaluations largely relied on estimates from single studies or informal rapid literature reviews.

METHODS

We conducted a systematic review of articles up to June 2016 to identify costs and utility estimates admissible for an economic evaluation from a single-payer healthcare provider's perspective. Meta-analyses were performed for studies that used same utility elicitation tools for similar diseases. Costs were adjusted to 2016/2017 US$.

RESULTS

Sixty-one papers (35 costs; 24 utilities; 2 costs and utilities) were selected from 10 742 initial records. Cost per case ranges were US$124-US$883 (anogenital warts), US$6912-US$52 579 (head and neck cancers), US$12 936-US$51 571 (anal cancer), US$17 524-34 258 (vaginal cancer), US$14 686-US$28 502 (vulvar cancer) and US$9975-US$27 629 (penile cancer). The total cost for 14 adult patients with recurrent respiratory papillomatosis was US$137 601 (one paper).Utility per warts episode ranged from 0.651 to 1 (12 papers, various utility elicitation methods), with pooled mean EQ-5D and EQ-VAS of 0.86 (95% CI 0.85 to 0.87) and 0.74 (95% CI 0.74 to 0.75), respectively. Fifteen papers reported utilities in head and neck cancers with range 0.29 (95% CI 0.0 to 0.76) to 0.94 (95% CI 0.3 to 1.0). Mean utility reported ranged from 0.5 (95% CI 0.4 to 0.61) to 0.65 (95% CI 0.45 to 0.75) (anal cancer), 0.59 (95% CI 0.54 to 0.64) (vaginal cancer), 0.65 (95% CI 0.60 to 0.70) (vulvar cancer) and 0.79 (95% CI 0.74 to 0.84) (penile cancer).

CONCLUSIONS

Differences in values reported from each paper reflect variations in cancer site, disease stages, study population, treatment modality/setting and utility elicitation methods used. As patient management changes over time, corresponding effects on both costs and utility need to be considered to ensure health economic assumptions are up-to-date and closely reflect the case mix of patients.

Clinical effectiveness and cost-effectiveness of interventions for the treatment of anogenital warts: systematic review and economic evaluation

BACKGROUND

Typically occurring on the external genitalia, anogenital warts (AGWs) are benign epithelial skin lesions caused by human papillomavirus infection. AGWs are usually painless but can be unsightly and physically uncomfortable, and affected people might experience psychological distress. The evidence base on the clinical effectiveness and cost-effectiveness of treatments for AGWs is limited.

OBJECTIVES

To systematically review the evidence on the clinical effectiveness of medical and surgical treatments for AGWs and to develop an economic model to estimate the cost-effectiveness of the treatments.

DATA SOURCES

Electronic databases (MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library databases and Web of Science) were searched from inception (or January 2000 for Web of Science) to September 2014. Bibliographies of relevant systematic reviews were hand-searched to identify potentially relevant studies. The World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov were searched for ongoing and planned studies.

REVIEW METHODS

A systematic review of the clinical effectiveness literature was carried out according to standard methods and a mixed-treatment comparison (MTC) undertaken. The model implemented for each outcome was that with the lowest deviance information criterion. A de novo economic model was developed to assess cost-effectiveness from the perspective of the UK NHS. The model structure was informed through a systematic review of the economic literature and in consultation with clinical experts. Effectiveness data were obtained from the MTC. Costs were obtained from the literature and standard UK sources.

RESULTS

Of 4232 titles and abstracts screened for inclusion in the review of clinical effectiveness, 60 randomised controlled trials (RCTs) evaluating 19 interventions were included. Analysis by MTC indicated that ablative techniques were typically more effective than topical interventions at completely clearing AGWs at the end of treatment. Podophyllotoxin 0.5% solution (Condyline(®), Takeda Pharmaceutical Company Ltd; Warticon(®) solution, Stiefel Laboratories Ltd) was found to be the most effective topical treatment evaluated. Networks for other outcomes included fewer treatments, which restrict conclusions on the comparative effectiveness of interventions. In total, 84 treatment strategies were assessed using the economic model. Podophyllotoxin 0.5% solution first line followed by carbon dioxide (CO2) laser therapy second line if AGWs did not clear was most likely to be considered a cost-effective use of resources at a willingness to pay of £20,000-30,000 per additional quality-adjusted life-year gained. The result was robust to most sensitivity analyses conducted.

LIMITATIONS

Limited reporting in identified studies of baseline characteristics for the enrolled population generates uncertainty around the comparability of the study populations and therefore the generalisability of the results to clinical practice. Subgroup analyses were planned based on type, number and size of AGWs, all of which are factors thought to influence treatment effect. Lack of data on clinical effectiveness based on these characteristics precluded analysis of the differential effects of treatments in the subgroups of interest. Despite identification of 60 studies, most comparisons in the MTC are informed by only one RCT. Additionally, lack of head-to-head RCTs comparing key treatments, together with minimal reporting of results in some studies, precluded comprehensive analysis of all treatments for AGWs.

CONCLUSIONS

The results generated by the MTC are in agreement with consensus opinion that ablative techniques are clinically more effective at completely clearing AGWs after treatment. However, the evidence base informing the MTC is limited. A head-to-head RCT that evaluates the comparative effectiveness of interventions used in clinical practice would help to discern the potential advantages and disadvantages of the individual treatments. The results of the economic analysis suggest that podophyllotoxin 0.5% solution is likely to represent a cost-effective first-line treatment option. More expensive effective treatments, such as CO2 laser therapy or surgery, may represent cost-effective second-line treatment options. No treatment and podophyllin are unlikely to be considered cost-effective treatment options. There is uncertainty around the cost-effectiveness of treatment with imiquimod, trichloroacetic acid and cryotherapy.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005457.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

The costs of managing genital warts in the UK by devolved nation: England, Scotland, Wales and Northern Ireland

Genital warts, 90% of which are caused by human papillomavirus types 6 and 11, are a significant problem in the UK. The cost of managing genital warts was previously estimated at £52.4 million for 2010. The objective of this study was to estimate the cost of genital warts management up to 2012 in the UK and by jurisdiction. Population statistics and the number of reported genital warts cases in genito-urinary medicine clinics were obtained and extrapolated to 2012. Cases of genital warts treated in primary care were estimated from The Health Improvement Network database. The number of visits and therapy required were estimated by genito-urinary medicine experts. Costs were obtained from the appropriate national tariffs. The model estimated there were 220,875 genital warts cases in the UK in 2012, costing £58.44 million (£265/patient). It estimated 157,793 cases in England costing £41.74 million; 7468 cases in Scotland costing £1.90 million; 7095 cases in Wales costing £1.87 million; and 3621 cases in Northern Ireland costing £948,000. The full National Health Service costs for the management of genital warts have never previously been estimated separately for each jurisdiction. Findings reveal a significant economic burden, which is important to quantify when understanding the value of quadrivalent human papilloma virus vaccination.

The natural history of genital human papillomavirus among HIV-negative men having sex with men and men having sex with women

BACKGROUND

Although human immunodeficiency virus (HIV)-negative men having sex with men (MSM) bear a substantial burden of human papillomavirus (HPV)-associated disease, prospective studies of genital HPV infection in this population are scarce.

METHODS

HPV genotyping was conducted on genital samples from men (aged 18-70 years) from Brazil, Mexico, or the United States who provided specimens at 6-month intervals for up to 4 years. Eligibility criteria included no history of genital warts or HIV infection. Evaluable specimens were collected from 564 MSM and 3029 men having sex with women (MSW). Incidence and clearance estimates with 95% confidence intervals were calculated.

RESULTS

The 12-month cumulative incidence of genital HPV was high in both MSM (25%; 95% confidence interval, 21%-30%) and MSW (21%; 20%-23%). After stratifying by city, MSM and MSW incidence rates were comparable, with 3 exceptions where MSM had higher incidence in ≥1 city: the group of quadrivalent vaccine types, HPV-45, and HPV-11. Median times to HPV-16 clearance were also comparable, with point estimates of >6 months for both MSM and MSW.

CONCLUSIONS

Unlike with many other sexually transmitted infections, genital HPV natural history may be similar in HIV-negative MSM and MSW. Study periods of ≤6 months, however, may not be long enough to accurately measure the persistence of these infections in men.

The theoretical impact and cost-effectiveness of vaccines that protect against sexually transmitted infections and disease

Sexually transmitted diseases, a source of widespread morbidity and sometimes mortality, are caused by a diverse group of infections with a common route of transmission. Existing vaccines against hepatitis B virus (HBV) and human papilloma virus 16, 18, 6 and 11 are highly efficacious and cost effective. In reviewing the potential role for other vaccines against sexually transmitted infections (STIs) a series of questions needs to be addressed about the burden of disease, the potential characteristics of a new vaccine, and the impact of other interventions. These questions can be viewed in the light of the population dynamics of sexually transmitted infections as a group and how a vaccine can impact these dynamics. Mathematical models show the potential for substantial impact, especially if vaccines are widely used. To better make the case for sexually transmitted infection vaccines we need better data and analyses of the burden of disease, especially severe disease. However, cost effectiveness analyses using a wide range of assumptions show that STI vaccines would be cost effective and their development a worthwhile investment.

HPV and HPV-associated diseases

Human papillomavirus (HPV) is the most common sexually transmitted infection. HPV is associated with a significant burden of disease and cancer, including anogenital warts and recurrent respiratory papillomatosis, and anogenital and oropharyngeal cancers. Effective prevention is available, including primary prevention of cancers and anogenital warts through HPV vaccination, and secondary prevention of cervical cancer through screening and treatment of precancer. This article focuses on HPV infection and the clinical consequences of infection, with attention to cervical and anogenital squamous intraepithelial neoplasia and anogenital warts.

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.

Inclusion of the benefits of enhanced cross-protection against cervical cancer and prevention of genital warts in the cost-effectiveness analysis of human papillomavirus vaccination in the Netherlands

Background

Infection with HPV 16 and 18, the major causative agents of cervical cancer, can be prevented through vaccination with a bivalent or quadrivalent vaccine. Both vaccines provide cross-protection against HPV-types not included in the vaccines. In particular, the bivalent vaccine provides additional protection against HPV 31, 33, and 45 and the quadrivalent vaccine against HPV31. The quadrivalent vaccine additionally protects against low-risk HPV type 6 and 11, responsible for most cases of genital warts. In this study, we made an analytical comparison of the two vaccines in terms of cost-effectiveness including the additional benefits of cross-protection and protection against genital warts in comparison with a screening-only strategy.

Methods

We used a Markov model, simulating the progression from HPV infection to cervical cancer or genital warts. The model was used to estimate the difference in future costs and health effects of both HPV-vaccines separately.

Results

In a cohort of 100,000 women, use of the bivalent or quadrivalent vaccine (both at 50% vaccination coverage) reduces the cervical cancer incidence by 221 and 207 cases, corresponding to ICERs of €17,600/QALY and €18,900/QALY, respectively. It was estimated that the quadrivalent vaccine additionally prevents 4390 cases of genital warts, reducing the ICER to €16,300/QALY. Assuming a comparable willingness to pay for cancer and genital warts prevention, the difference in ICERs could justify a slightly higher price (~7% per dose) in favor of the quadrivalent vaccine.

Conclusions

Clearly, HPV vaccination has been implemented for the prevention of cervical cancer. From this perspective, use of the bivalent HPV vaccine appears to be most effective and cost-effective. Including the benefits of prevention against genital warts, the ICER of the quadrivalent HPV vaccine was found to be slightly more favourable. However, current decision-making on the introduction of HPV is driven by the primary cervical cancer outcome. New vaccine tenders could consider the benefits of cross-protection and the benefits of genital warts, which requires more balanced decision-making.

Acceptability of the human papillomavirus vaccine among urban adolescent males

The human papillomavirus (HPV) vaccine was recently approved for use in males. Certain groups, such as men who have sex with men (MSM), are at increased risk of HPV infection. The purpose of the study was to understand perceptions of HPV and the vaccine among adolescent and young adult males, both heterosexual and MSM. Seventy-six males (45 heterosexual, 31 MSM) completed a questionnaire and participated in a focus group. Overall, 42% had heard of HPV and 39% had heard of the HPV vaccine. Males had moderate to favorable attitudes toward vaccination, although intentions to vaccinate were more neutral. MSM were more knowledgeable, aware, and in control of the decision to vaccinate than heterosexual males. Increasing awareness and knowledge about HPV and the vaccine may be necessary to encourage vaccination; certain subgroups of males may be more receptive to HPV vaccination than others.

Evaluating the epidemiology and morbidity burden associated with human papillomavirus in Israel: accounting for CIN1 and genital warts in addition to CIN2/3 and cervical cancer

BACKGROUND

Human papillomavirus (HPV) infection is mostly associated with cervical cancer (CC). However, it can cause other illnesses as well, all of which impact on people's wellbeing and consume healthcare resources. Measures for prevention or early detection of these conditions differ in their effectiveness and cost. An informative evaluation of the projected benefit of these measures depends on understanding the current unmet need, not only limited to CC.

OBJECTIVE

To evaluate the burden of HPV-related conditions in Israel, including CC, cervical precancerous lesions and genital warts.

METHODS

A retrospective database analysis was conducted for the second largest health management organization (HMO) in Israel, covering approximately 1.8 million people. Records were drawn following a search for key words indicative of related diagnoses, lab results, medications, or procedures for the time period of 2006-2008. Prevalence, incidence and resource utilization were analysed. Findings were extrapolated to the whole Israeli population using age and gender incidence rates.

RESULTS

Incidence of CC was found to be 5 per 100,000 females. Incidences of cervical intraepithelial neoplasia (CIN) grades 1, 2 and 3 were 74, 27 and 36 per 100,000 females, respectively. Incidence of genital warts was 239 and 185 per 100,000 for men and women, respectively. The overall annual economic burden was calculated to be $US48,838,058 (year 2010 values).

CONCLUSIONS

HPV poses a significant burden in terms of health (clinical and quality of life) and in monetary terms, even for conditions that are sometimes regarded as benign, such as CIN1 or genital warts. Current findings should be used for proper evaluation of measures to reduce HPV-related morbidity and mortality, such as regular screening and vaccination.

Economic and humanistic burden of external genital warts

External genital warts (EGW) are a sexually transmitted infection caused by various strains of human papillomavirus (HPV). Several studies have described the direct and indirect costs of EGW, while others have reported on the burden of EGW in terms of the impact on the quality of life (QOL) of patients. The arrival of a quadrivalent HPV vaccine that protects against both cervical cancer and EGW requires a proper understanding of the impact of vaccines on costs and QOL. Using pre-defined search terms and inclusion/exclusion criteria, we performed a systematic review of the economic and humanistic burden of EGW. The focus of our review was on literature describing the direct and indirect costs of EGW per episode of care (EoC) or per year, as well as the impact of EGW on disease-specific, generic, or preference-based QOL measures. We also reviewed the literature on the national economic burden of EGW from the perspectives of different countries. Other aspects of EGW management that can inform economic modelling studies, such as length of EoC, number of physician visits and indirect costs, were also explored. Our review sheds light on the high economic and humanistic burden of EGW and important differences in the costs between men and women, as well as the differences in health resource utilization and costs across countries. Our study also highlights the dearth of information on the impact of EGW on the QOL and productivity of patients.

Imiquimod 3.75% cream applied daily to treat anogenital warts: combined results from women in two randomized, placebo-controlled studies

OBJECTIVE

To evaluate if new imiquimod formulations using a shorter treatment duration are safe and efficacious to treat anogenital warts.

METHODS

In two studies 534 women ≥12 years of age (mean 33.4) with 2-30 warts (mean 7.9) and total wart area ≥10 mm(2) (mean 166.3) were randomized (1:2:2) to placebo (106), imiquimod 2.5% (212) or 3.75% (216) creams applied once daily until complete clearance or a maximum of 8 weeks.

RESULTS

For placebo, imiquimod 2.5% and 3.75%, respectively, complete clearance of all warts was achieved in 14.2%, 28.3%, and 36.6% of women (intent-to-treat, P = 0.008 imiquimod 2.5%, and P < 0.001 3.75% versus placebo). Mean changes in wart counts were -10.7%, -50.9%, and -63.5% (per-protocol, P < 0.001 each active versus placebo) and safety-related discontinuation rates 0.9%, 1.4%, and 2.3%.

CONCLUSIONS

Imiquimod 3.75% applied daily for up to 8 weeks was well tolerated and superior to placebo in treating women with external anogenital warts.

The cost-effectiveness of male HPV vaccination in the United States

INTRODUCTION

The objective of this study was to estimate the cost-effectiveness of adding human papillomavirus (HPV) vaccination of 12-year-old males to a female-only vaccination program for ages 12-26 years in the United States.

METHODS

We used a simplified model of HPV transmission to estimate the reduction in the health and economic burden of HPV-associated diseases in males and females as a result of HPV vaccination. Estimates of the incidence, cost-per-case, and quality-of-life impact of HPV-associated health outcomes were based on the literature. The HPV-associated outcomes included were: cervical intraepithelial neoplasia (CIN); genital warts; juvenile-onset recurrent respiratory papillomatosis (RRP); and cervical, vaginal, vulvar, anal, oropharyngeal, and penile cancers.

RESULTS

The cost-effectiveness of male vaccination depended on vaccine coverage of females. When including all HPV-associated outcomes in the analysis, the incremental cost per quality-adjusted life year (QALY) gained by adding male vaccination to a female-only vaccination program was $23,600 in the lower female coverage scenario (20% coverage at age 12 years) and $184,300 in the higher female coverage scenario (75% coverage at age 12 years). The cost-effectiveness of male vaccination appeared less favorable when compared to a strategy of increased female vaccination coverage. For example, we found that increasing coverage of 12-year-old girls would be more cost-effective than adding male vaccination even if the increased female vaccination strategy incurred program costs of $350 per additional girl vaccinated.

CONCLUSIONS

HPV vaccination of 12-year-old males might potentially be cost-effective, particularly if female HPV vaccination coverage is low and if all potential health benefits of HPV vaccination are included in the analysis. However, increasing female coverage could be a more efficient strategy than male vaccination for reducing the overall health burden of HPV in the population.

Quadrivalent human papillomavirus (HPV) types 6, 11, 16, 18 vaccine: for the prevention of genital warts in males

The quadrivalent HPV types 6, 11, 16, 18 vaccine (Gardasil®) is a recombinant vaccine comprising purified virus-like particles derived from the L1 capsid proteins of HPV types 6, 11, 16 and 18. The vaccine was highly immunogenic. Geometric mean titres (GMTs) and seroconversion rates for all four HPV types at month 7 in males aged 10-15 years were noninferior to those in females aged 16-23 years, and those in males aged 9-15 years were noninferior to those in females aged 9-15 years. In addition, GMTs and seroconversion rates in males aged 16-26 years receiving the vaccine were higher than those receiving amorphous aluminium hydroxyphosphate sulfate adjuvant (AAHS) control. The quadrivalent HPV vaccine was significantly more effective than AAHS control at decreasing the incidence of HPV 6-, 11-, 16- or 18-related external genital lesions (primary endpoint) in a randomized, double-blind, placebo-controlled, multicentre study in males aged 16-26 years. The most common clinical endpoint was HPV 6- and 11-related condyloma; efficacy was robust against these lesions. The vaccine is also expected to be protective against genital warts in males aged 9-15 years, as the immune response in males of this age group was noninferior to that in males aged 16-26 years. The quadrivalent HPV vaccine was generally well tolerated in males aged 9-26 years. The most common adverse events reported were injection-site related, and most of these were of mild to moderate severity.

The impact of genital warts: loss of quality of life and cost of treatment in eight sexual health clinics in the UK

OBJECTIVES

To estimate the loss of quality of life and cost of treatment associated with genital warts seen in sexual health clinics.

METHODS

A cross-sectional questionnaire study and case note review of individuals with genital warts, carried out in eight sexual health clinics in England and Northern Ireland. Individuals with genital warts attending the participating clinics were invited to take part in the questionnaire study. 895 participants were recruited. A separate sample of 370 participants who had attended a participating clinic with a first visit for a first or recurrent episode of genital warts between April and June 2007 was included in the case note review. Quality of life was measured using the EQ-5D questionnaire and the cost of an episode of care was derived from the case note review.

RESULTS

The weighted mean EQ-5D index score was 0.87 (95% CI 0.85 to 0.89). The weighted mean disutility was 0.056 (95% CI 0.038 to 0.074). The estimated mean loss of quality-adjusted life-years associated with an episode of genital warts was 0.018 (95% CI 0.0079 to 0.031), equivalent to 6.6&emsp14;days of healthy life lost per episode. The weighted mean cost per episode of care was £94 (95% CI £84 to £104), not including the cost of a sexually transmitted infection screen.

CONCLUSIONS

Genital warts have a substantial impact on the health service and the individual. This information can be utilised for economic evaluation of human papillomavirus vaccination.

The United Kingdom Joint Committee on Vaccination and Immunisation

The United Kingdom Joint Committee on Vaccination and Immunisation provides advice to the Ministers of Health on all aspects of vaccination. Under recent legislation a recommendation from the Committee confers the right to the vaccine concerned to the population of England Wales. A critical aspect of both advice and recommendations is that the vaccination is shown to reach a cost-effectiveness threshold. This usually requires sophisticated mathematical modelling and economics.

Targeted human papillomavirus vaccination of men who have sex with men in the USA: a cost-effectiveness modelling analysis

BACKGROUND

A vaccine targeting human papillomavirus (HPV) types 16 and 18, which are associated with 80% of anal cancers, is efficacious in men. High-risk populations such as men who have sex with men (MSM) might especially benefit from vaccination. I aimed to estimate the cost-effectiveness of HPV vaccination of MSM in the USA.

METHODS

I constructed decision-analytic models to estimate the direct health and economic outcomes of HPV vaccination (against types 6, 11, 16, and 18) for prevention of HPV-related anal cancer and genital warts. The model parameters that were varied were age at vaccination (12 years, 20 years, and 26 years), previous exposure to vaccine-targeted HPV types, and prevalence of HIV-1. I used the models to conduct sensitivity analyses, including duration of vaccine protection, vaccine cost, and burden of anal cancer and genital warts.

FINDINGS

In a scenario of HPV vaccination of MSM at 12 years of age without previous exposure to HPV, compared with no vaccination, vaccination cost US$15,290 per quality-adjusted life-year gained. In scenarios where MSM are vaccinated at 20 years or 26 years of age, after exposure to HPV infections, the cost-effectiveness ratios worsened, but were less than $50,000 per quality-adjusted life-year under most scenarios. For example, HPV vaccination of MSM at 26 years cost $37,830 per quality-adjusted life-year when previous exposure to all vaccine-targeted HPV types was assumed to be 50%. Outcomes were most sensitive to variations in anal cancer incidence, duration of vaccine protection, and HIV prevalence in MSM.

INTERPRETATION

HPV vaccination of MSM is likely to be a cost-effective intervention for the prevention of genital warts and anal cancer.

FUNDING

US National Cancer Institute.