Targeting human papillomavirus to reduce the burden of cervical, vulvar and vaginal cancer and pre-invasive neoplasia: establishing the baseline for surveillance.

BACKGROUND: Infection with high-risk human papillomavirus (HPV) is causally related to cervical, vulvar and vaginal pre-invasive neoplasias and cancers. Highly effective vaccines against HPV types 16/18 have been available since 2006, and are currently used in many countries in combination with cervical cancer screening to control the burden of cervical cancer. We estimated the overall and age-specific incidence rate (IR) of cervical, vulvar and vaginal cancer and pre-invasive neoplasia in Denmark, Iceland, Norway and Sweden in 2004-2006, prior to the availability of HPV vaccines, in order to establish a baseline for surveillance. We also estimated the population attributable fraction to determine roughly the expected effect of HPV16/18 vaccination on the incidence of these diseases. METHODS: Information on incident cervical, vulvar and vaginal cancers and high-grade pre-invasive neoplasias was obtained from high-quality national population-based registries. A literature review was conducted to define the fraction of these lesions attributable to HPV16/18, i.e., those that could be prevented by HPV vaccination. RESULTS: Among the four countries, the age-standardised IR/105 of cervical, vaginal and vulvar cancer ranged from 8.4-13.8, 1.3-3.1 and 0.2-0.6, respectively. The risk for cervical cancer was highest in women aged 30-39, while vulvar and vaginal cancers were most common in women aged 70+. Age-standardised IR/105 of cervical, vulvar and vaginal pre-invasive neoplasia ranged between 138.8-183.2, 2.5-8.8 and 0.5-1.3, respectively. Women aged 20-29 had the highest risk for cervical pre-invasive neoplasia, while vulvar and vaginal pre-invasive neoplasia peaked in women aged 40-49 and 60-69, respectively. Over 50% of the observed 47,820 incident invasive and pre-invasive cancer cases in 2004-2006 can be attributed to HPV16/18. CONCLUSION: In the four countries, vaccination against HPV 16/18 could prevent approximately 8500 cases of gynecological cancer and pre-cancer annually. Population-based cancer and vaccination registries are essential to assess the predicted public health effects of HPV vaccination.

The Cost-Effectiveness Analysis of a Quadrivalent Human Papillomavirus Vaccine (6/11/16/18) for Females in Japan.

OBJECTIVE: We assessed the epidemiological and economic impact of a quadrivalent human papillomavirus (HPV) (6/11/16/18) vaccine for females in preventing cervical cancer, cervical intraepithelial neoplasia grades 2 and 3 (CIN 2/3), cervical intraepithelial neoplasia grade 1 (CIN 1), and genital warts in Japan by using a transmission dynamic model. METHODS: A published mathematical model of the transmission dynamics of HPV infection and disease was adapted for Japan. Model inputs were used from Japan or the Asia/Pacific region when available; otherwise, the default values in the original model were used. The transmission dynamic model was used to assess the epidemiological and economic impact of a quadrivalent HPV (6/11/16/18) vaccine for females in preventing cervical cancer, CIN 2/3, CIN 1, and genital warts in Japan.Maintaining current cervical cancer screening practices, we evaluated two strategies: routine vaccination of females by age 12 years (S1), and S1 combined with a temporary (5 years) female catch-up program for age 12 to 24 years (S2). The vaccine coverage rate was 80% for the routine and 50% for the catch-up vaccination programs. RESULTS: Compared with no vaccination, both vaccination strategies significantly reduced the incidence of HPV 6/11/16/18-related disease. The most effective strategy was S2. By using this strategy over 100 years in the Japanese population, the estimated cumulative percentage reduction in incident HPV 6/11/16/18-related genital warts-female, genital warts-male, cervical CIN 1, CIN 2/3, and cervical cancer cases was 90% (2,113,723 cases), 86% (2,082,637 cases), 72% (263,406 cases), 71% (1,328,366 cases), and 58% (323,145 cases), respectively. The cost-effectiveness ratios were JPY 1,244,000, and JPY 1,205,800 per quality-adjusted life-year gained for S1 and S2 compared with no vaccination, respectively, over a time horizon of 100 years. CONCLUSION: We conclude that a quadrivalent HPV vaccination program for females can reduce the incidence of cervical cancer, CIN, and genital warts in Japan at a cost-per-quality-adjusted life-year ratio within the range defined as cost-effective.

Impact of vaccinating boys and men against HPV in the United States.

We assessed the public health impact and value of vaccinating boys and men with the quadrivalent HPV vaccine in the United States. We used mathematical population models, accounting for both the direct and indirect protective effects of vaccination. Inputs for the models were obtained from public data sources, published literature, and analyses of clinical trial data. Compared with a program of vaccinating girls and women only, including boys and men 9-26 years of age would further decrease the cumulative mean number of genital wart cases, cervical intraepithelial neoplasia 2/3 cases, cancer cases, and cancer deaths by 5,146,000, 708,000, 116,000, and 40,000, respectively, within 100 years. The mean cost-effectiveness ratio (2008 US $) of this strategy was $25,700 (range: 13,600-48,800) per QALY gained if vaccination protects against all HPV 6/11/16/18-associated diseases, and $69,000 (range: 37,700-152,300)/QALY if it only protects against diseases currently in the vaccine indication. Vaccinating boys and men age 9-26 against all HPV 6/11/16/18-associated diseases provides substantial public health benefits and is cost-effective at commonly cited thresholds.

The cost effectiveness of a quadrivalent human papillomavirus vaccine (6/11/16/18) in Hungary.

OBJECTIVE: A transmission dynamic model was used to assess the epidemiological and economic impact of a quadrivalent human papillomavirus (HPV) (6/11/16/18) vaccine in preventing cervical cancer, cervical intraepithelial neoplasia grades 2 and 3 (CIN 2/3), CIN 1 and genital warts in Hungary. METHODS: The routine vaccination of 12-year-old girls and the routine vaccination of 12-year-old girls plus a temporary catch-up programme for girls and women aged 12-24 years was evaluated. RESULTS: The model projected that at year 100, both strategies could reduce the incidence of HPV 6/11/16/18-related cervical cancer, CIN 2/3, CIN 1 and genital warts cases among Hungarian women by 90%, 90%, 85% and 93%, respectively. Twenty-five years after the introduction of HPV vaccination in the population, routine vaccination of girls by the age of 12 reduced the cumulative number of cases of cervical cancer, CIN 2/3, CIN 1 and genital warts by 685, 13,473, 3,423 and 163,987, respectively. The incremental cost-effectiveness ratios of the two vaccination strategies were €9,577 and €10,646 per quality-adjusted life-year (QALY) gained over a time horizon of 100 years. KEY LIMITATIONS: The model did not account for the health and economic impact of other HPV diseases which may result from HPV 16, 18, 6, and 11 infections such as vaginal, vulvar, penile, anal and head-neck cancers, and recurrent respiratory papillomatosis. Epidemiological data from Hungary on these other HPV diseases as well genital warts are needed. CONCLUSION: A quadrivalent HPV vaccination programme can reduce the incidence of cervical cancer, CIN and genital warts in Hungary at a cost-per-QALY ratio within the range defined as cost effective.

Epidemiologic natural history and clinical management of Human Papillomavirus (HPV) Disease: a critical and systematic review of the literature in the development of an HPV dynamic transmission model.

BACKGROUND: Natural history models of human papillomavirus (HPV) infection and disease have been used in a number of policy evaluations of technologies to prevent and screen for HPV disease (e.g., cervical cancer, anogenital warts), sometimes with wide variation in values for epidemiologic and clinical inputs. The objectives of this study are to: (1) Provide an updated critical and systematic review of the evidence base to support epidemiologic and clinical modeling of key HPV disease-related parameters in the context of an HPV multi-type disease transmission model which we have applied within a U.S. population context; (2) Identify areas where additional studies are particularly needed. METHODS: Consistent with our and other prior HPV natural history models, the literature review was confined to cervical disease and genital warts. Between October 2005 and January 2006, data were gathered from the published English language medical literature through a search of the PubMed database and references were examined from prior HPV natural history models and review papers. Study design and data quality from individual studies were compared and analyses meeting pre-defined criteria were selected. RESULTS: Published data meeting review eligibility criteria were most plentiful for natural history parameters relating to the progression and regression of cervical intraepithelial neoplasia (CIN) without HPV typing, and data concerning the natural history of HPV disease due to specific HPV types were often lacking. Epidemiologic evidence to support age-dependency in the risk of progression and regression of HPV disease was found to be weak, and an alternative hypothesis concerning the time-dependence of transition rates is explored. No data were found on the duration of immunity following HPV infection. In the area of clinical management, data were observed to be lacking on the proportion of clinically manifest anogenital warts that are treated and the proportion of cervical cancer cases that become symptomatic by stage. CONCLUSION: Knowledge of the natural history of HPV disease has been considerably enhanced over the past two decades, through the publication of an increasing number of relevant studies. However, considerable opportunity remains for advancing our understanding of HPV natural history and the quality of associated models, particularly with respect to examining HPV age- and type-specific outcomes, and acquired immunity following infection.

Age-based programs for vaccination against HPV.

BACKGROUND: The risk of infection with human papillomavirus (HPV) increases with age. Answering the question of which age groups are appropriate to target for catch-up vaccination with the newly licensed quadrivalent HPV vaccine (types 6/11/16/18) will be important for developing vaccine policy recommendations. OBJECTIVES: To assess the value of varying female HPV vaccination strategies by specific age groups of a catch-up program in the United States. METHODS: The authors used previously published mathematical population dynamic model and cost-utility analysis to evaluate the public health impact and cost-effectiveness of alternative quadrivalent HPV (6/11/16/18) vaccination strategies. The model simulates heterosexual transmission of HPV infection and occurrence of cervical intraepithelial neoplasia (CIN), cervical cancer, and external genital warts in an age-structured population stratified by sex and sexual activity groups. The cost-utility analysis estimates the cost of vaccination, screening, diagnosis, and treatment of HPV diseases, and quality-adjusted survival. RESULTS: Compared with the current screening practices, vaccinating girls and women ages 12 to 24 years was the most effective strategy, reducing the number of HPV6/11/16/18-related genital warts, CIN grades 2 and 3, and cervical cancer cases among women in the next 25 years by 3,049,285, 1,399,935, and 30,021; respectively. The incremental cost-effectiveness ratio of this strategy when compared with vaccinating girls and women ages 12 to 19 years was $10,986 per quality-adjusted life-year gained. CONCLUSION;: Relative to other commonly accepted health-care programs, vaccinating girls and women ages 12 to 24 years appears cost-effective.

The cost-effectiveness of a quadrivalent human papillomavirus vaccine in Taiwan.

BACKGROUND: A quadrivalent human papillomavirus (HPV 6/11/16/18) vaccine has recently received regulatory approval in Taiwan for the prevention of cervical carcinoma, high-grade cervical dysplasia (cervical intraepithelial neoplasia 2/3 [CIN 2/3]), low-grade cervical dysplasia (CIN 1), high-grade vulvar and vaginal dysplasia, and external genital warts. OBJECTIVE: To examine the potential long-term epidemiologic and economic consequences of a quadrivalent HPV (6/11/16/18) vaccination program in Taiwan. METHODS: A transmission dynamic model was used to estimate the long-term epidemiologic and economic consequences of quadrivalent HPV vaccination. Two vaccination strategies were evaluated in conjunction with current cervical cancer screening: 1) vaccination of 12-year-old girls and 2) vaccination of 12-year-old girls with a temporary 5-year catch-up vaccination of females aged 12-24 years (catch-up). RESULTS: From an epidemiologic perspective, both vaccination strategies reduce the overall incidence of HPV 16/18-related cervical cancer relative to no vaccination by 91% during year 100 following vaccine introduction. Likewise, both vaccination strategies reduce the incidence of CIN 2/3, CIN 1, and genital warts by approximately 90%, 86%, and 94%, respectively, at this time point. However, the catch-up program consistently achieves greater benefit earlier than the 12-year-old program. The catch-up strategy is both more effective and efficient than the strategy that vaccinates 12-year-old girls only, with an incremental cost-effectiveness ratio of New Taiwan dollars (NT$) 410,477 per quality-adjusted life-year gained. CONCLUSIONS: The results from this model suggest that in Taiwan, prophylactic HPV 6/11/16/18 vaccination of females can: 1) substantially reduce genital warts, CIN, and cervical cancer; 2) improve quality of life and survival; and 3) be cost-effective when implemented as a vaccination strategy that includes a temporary catch-up program.

A multi-type HPV transmission model.

A prophylactic quadrivalent (types 6/11/16/18) vaccine against oncogenic and warts-causing genital Human papillomavirus (HPV) types was approved by the US Food and Drug Administration in 2006. This paper presents a nonlinear, deterministic, age-structured, mathematical model of the transmission dynamics of HPV and disease occurrence in a US population stratified by gender and sexual activity group. The model can assess both the epidemiologic consequences and cost effectiveness of alternative vaccination strategies in a setting of organized cervical cancer screening in the United States. Inputs for the model were obtained from public data sources, published literature, and analyses of clinical trial data. The results suggest that a prophylactic quadrivalent HPV vaccine can: (i) substantially reduce the incidence of disease, (ii) increase survival among females, (iii) improve quality of life for both males and females, (iv) be cost-effective when administered to females age 12-24 years, and (v) be cost-effective when implemented as a strategy that combines vaccination of both females and males before age 12 vaccination with a 12 to 24 years of age catch-up vaccination program.

Structural differences among cost-effectiveness models of human papillomavirus vaccines.

In this article we compare previously published cost-effectiveness studies of human papillomavirus (HPV) vaccines along a defined subset of key model structural assumptions relating to HPV infection and disease, cervical cancer screening and HPV vaccination. For each structural aspect examined, we summarize assumptions from each study, provide a critical review and discuss the impact upon results. Considerable variation was observed across HPV vaccine cost-effectiveness models in a number of influential assumptions. Holding constant factors for which current data are lacking, the combined impact of assumptions made for the remaining parameters examined would appear to tend toward underestimation of the cost-effectiveness of HPV vaccination within existing studies. However, uncertainty concerning parameters, such as the duration of vaccine protection and acquired immunity following HPV infection, and the relationship between age and HPV virulence, complicates precise estimation of the cost-effectiveness of HPV vaccination and rigorous evaluation of the validity of existing modeling results.

Reductions in human papillomavirus-disease resource use and costs with quadrivalent human papillomavirus (types 6, 11, 16, and 18) recombinant vaccination: the FUTURE Study Economic Evaluation.

OBJECTIVE: To examine the short-term impact of quadrivalent human papillomavirus (HPV) (types 6/11/16/18) recombinant vaccination upon HPV disease-related health-care resource utilization and costs among young women. METHODS: We analyzed data from a randomized clinical trial comparing quadrivalent vaccination to placebo, among women (N = 7861) primarily 16 to 23 years of age at enrollment. HPV disease episodes, health-care resource utilization and costs associated with cervical, vaginal, and vulvar precancers, and anogenital warts were analyzed over a period of 2.5 years among women, regardless of baseline HPV status. RESULTS: Overall, there was a 25.9% (P < 0.001) reduction in total HPV disease-related health-care costs among women receiving vaccine versus placebo (absolute reduction $3939 per 100 trial enrollees). We observed similar overall reductions in HPV-disease episodes and resource utilization. There was a statistically significant reduction in HPV 6/11-related disease episode costs of 65.1% ($1837 per 100), and a reduction of 51.4% ($1781 per 100) in HPV 16/18-related episode costs. CONCLUSIONS: Quadrivalent HPV vaccination can reduce HPV disease events, resource use and costs when administered to a broad population of young women 16 to 23 years of age. Prevention of HPV types 6 and 11 yielded similar value in terms of HPV disease cost offsets, compared to protection against HPV 16 and 18, during the years initially after vaccination. Over the short-term, costs of vaccination exceed cost offsets associated with prevention of HPV disease; however, quadrivalent HPV vaccination has previously been shown to be cost-effective in the longer term, when fully accounting for health benefits and cost offsets.

Assessment of the cost-effectiveness of a quadrivalent HPV vaccine in Norway using a dynamic transmission model.

To assess the epidemiological and economic impact of alternative quadrivalent human papillomavirus (HPV) vaccine strategies in Norway, we adapted a previously published dynamic transmission model. Vaccination of girls and women aged 12-24 years reduced the incidence of HPV 6/11/16/18-related genital warts, cervical intraepithelial neoplasia and cervical cancer by 94, 92 and 92% by year 100, respectively. The cost-effectiveness ratio for this strategy when compared with vaccinating girls before the age of 12 years only was 63,294 Norwegian kroner (euro8272) per QALY gained. Based on this model and assumptions, implementation of a quadrivalent HPV vaccine national program in Norway could reduce the incidence of cervical cancer, cervical intraepithelial neoplasia and genital warts at a cost-effectiveness ratio within the range accepted as cost effective.

Cost-effectiveness of quadrivalent human papillomavirus (HPV) vaccination in Mexico: a transmission dynamic model-based evaluation.

We examined the potential health outcomes and cost-effectiveness of quadrivalent human papillomavirus (HPV) 6/11/16/18 vaccination strategies in the Mexican population using a multi-HPV type dynamic transmission model. Assuming similar cervical screening practices, with or without vaccination, we examined the incremental cost-effectiveness of vaccination strategies for 12 year-old females, with or without male vaccination, and temporary age 12-24 catch-up vaccination for females or both sexes. The most effective strategy therein was vaccination of 12-year-olds, plus a temporary 12-24-year-old catch-up program covering both sexes; whereby HPV 6/11/16/18-related cervical cancer, high-grade cervical precancer, and genital wart incidence was reduced by 84-98% during year 50 following vaccine introduction. Incremental cost-effectiveness ratios in the primary analyses ranged from approximately 3000 dollars (U.S.) per quality-adjusted life year (QALY) gained for female vaccination strategies to approximately 16000 dollars /QALY for adding male vaccination with catch-up.

Progression and regression of incident cervical HPV 6, 11, 16 and 18 infections in young women.

BACKGROUND: We describe type-specific progression, regression and persistence of incident human papillomavirus (HPV)-6-11-16 and -18 infections, along with type distribution in cervical intra-epithelial neoplasia (CIN) lesions. METHODS: The study population consisted of 16-23 year-old women undergoing Pap testing and cervical swab polymerase chain reaction testing for HPV DNA at approximate 6 month intervals for up to 4 years in the placebo arm of a clinical trial of an HPV 16-vaccine. HPV types in incident infections were correlated with types in lesion biopsy specimens. RESULTS: 56.7% of CIN-1 and nearly one-third of CIN-2/3 lesions following incident HPV-6-11-16 or -18 infections did not correlate with the incident infection HPV type. Cumulative 36-month progression rates to CIN-2/3 testing positive for the relevant HPV type were highest for HPV-16 infections (16.5%), followed by HPV-18 (8.2%). Overall, 26.0% of CIN-1, 50.0% of CIN-2 and 70.6% of CIN-3 biopsies tested positive for HPV-6-11-16-18 infections. CONCLUSION: Women with a given HPV type may often be co-infected or subsequently infected with other types which may lead to subsequent cervical lesions. This issue has been addressed in this study reporting data for the natural history of HPV-6-11-16 and -18 infections and is a relevant consideration in designing future studies to evaluate the incidence/risk of CIN following other type-specific HPV infections.

Incidence and duration of cervical human papillomavirus 6, 11, 16, and 18 infections in young women: an evaluation from multiple analytic perspectives.

OBJECTIVE: To estimate the incidence and duration of cervical human papillomavirus (HPV)-6, HPV-11, HPV-16, and HPV-18 infections in a population of young American women. METHODS: The study population consisted of U.S. women who at baseline were 16 to 23 years of age, reported zero to five lifetime sexual partners, never having been pregnant, and never having had a prior abnormal Papanicolaou test and were enrolled in the placebo arm of a randomized multicenter clinical trial of a HPV-16 L1 virus-like particle vaccine. Women underwent type-specific endocervical/ectocervical swab HPV DNA testing at approximately 6-month intervals for up to 48 months of follow-up. To contribute person-time in the analyses of type-specific HPV incidence, a woman must have had at least three satisfactory swab specimens available and been negative for the relevant HPV type (HPV-6, HPV-11, HPV-16, or HPV-18) on her first two trial swabs. The duration of incident HPV infections was estimated using Kaplan-Meier survival analysis methods. RESULTS: Person-years of exposure ranged by type-specific analysis from 2,645 to 3,188, with an incidence rate per 100 person-years of 3.6 for HPV-6, 0.4 for HPV-11, 5.4 for HPV-16, and 2.1 for HPV-18. With censoring at the time of treatment for cervical intraepithelial neoplasia, where done, the mean duration of incident infections was 9.3, 8.4, 18.2, and 16.4 months, respectively, for HPV-6 (n = 103), HPV-11 (n = 13), HPV-16 (n = 142), and HPV-18 (n = 62). When the duration of HPV infections was truncated at the time of cervical intraepithelial neoplasia detection (any grade), where applicable, mean duration figures were 8.4, 8.1, 14.0, and 15.1 months for HPV-6, HPV-11, HPV-16, and HPV-18 infections, respectively. CONCLUSIONS: Previous studies of the mean duration of cervical HPV infection have been based on prevalent infections and/or featured relatively short duration of follow-up. This study tested women for HPV infection over a period of up to 48 months and observed a mean duration of incident HPV-16/HPV-18 infections approximately twice that of HPV-6/HPV-11.

Model for assessing human papillomavirus vaccination strategies.

We present a transmission dynamic model that can assess the epidemiologic consequences and cost-effectiveness of alternative strategies of administering a prophylactic quadrivalent (types 6/11/16/18) human papillomavirus (HPV) vaccine in a setting of organized cervical cancer screening in the United States. Compared with current practice, vaccinating girls before the age of 12 years would reduce the incidence of genital warts (83%) and cervical cancer (78%) due to HPV 6/11/16/18. The incremental cost-effectiveness ratio (ICER) of augmenting this strategy with a temporary catch-up program for 12- to 24-year-olds was US $4,666 per quality-adjusted life year (QALY) gained. Relative to other commonly accepted healthcare programs, vaccinating girls and women appears cost-effective. Including men and boys in the program was the most effective strategy, reducing the incidence of genital warts, cervical intraepithelial neoplasia, and cervical cancer by 97%, 91%, and 91%, respectively. The ICER of this strategy was $45,056 per QALY.

Mathematical models for predicting the epidemiologic and economic impact of vaccination against human papillomavirus infection and disease.

Infection with human papillomavirus (HPV) is the primary cause of cervical cancer, other anogenital cancers, genital warts, and recurrent respiratory papillomatosis. Clinical studies have demonstrated that a prophylactic HPV vaccine can prevent infection, genital warts, and the precancerous lesions that lead to cervical cancer. Given the absence of data on the long-term effectiveness of HPV vaccination, a number of mathematical models have been developed to provide insight to policy makers by projecting the long-term epidemiologic and economic consequences of vaccination and evaluate alternative vaccination policies. This paper reviews the state of these models. Three types of HPV mathematical models have been reported in the literature: cohort, population dynamic, and hybrid. All have demonstrated that vaccination can significantly reduce the incidence of cervical cancer in the long term. However, only the cohort and hybrid models have evaluated the cost-effectiveness of vaccination strategies for preventing cervical cancer. These models have generally shown that vaccinating females can be cost-effective. None has accounted for the potential benefits of vaccinating the population to reduce the burden of recurrent respiratory papillomatosis and cancers of the vagina, vulva, anus, penis, and head/neck. Given that only the population dynamic model can account for both the direct and indirect (i.e., herd immunity effects) benefits of vaccination in the population, future research should focus on further development of dynamic models by expanding the range of epidemiologic outcomes tracked and including the ability to assess the cost-effectiveness of alternative vaccination policies.

Assessing the annual economic burden of preventing and treating anogenital human papillomavirus-related disease in the US: analytic framework and review of the literature.

The anogenital human papillomavirus (HPV) is estimated to be the most commonly occurring sexually transmitted infection in the US. Comprehensive estimates of the annual economic burden associated with the prevention and treatment of anogenital HPV-related disease in the US population are currently unavailable. The purpose of this paper is to (i) outline an analytic framework from which to estimate the annual economic burden of preventing and treating anogenital HPV-related disease in the US; (ii) review available US literature concerning the annual economic burden of HPV; and (iii) highlight gaps in current knowledge where further study is particularly warranted. Among eight US studies identified that describe the annual economic burden pertaining to one or more aspects of anogenital HPV-related disease, three met the review eligibility criteria (published between 1990 and 2004, examined multiple facets of annual anogenital HPV-related economic burden, and clearly articulated the data and methods used in the estimation process). All costs were adjusted to 2004 US dollars. Estimates of the annual direct medical costs associated with cervical cancer were comparable across studies (range 300-400 million US dollars). In contrast, there was a wide range across studies for estimates of the annual direct medical costs associated with cervical intraepithelial neoplasia (range 700 million US dollars-2.3 billion US dollars). Only one study reported direct medical costs for anogenital warts (200 million US dollars) and routine cervical cancer screening (2.3 billion US dollars). No studies examined direct medical costs attributable to HPV-related anal, penile, vaginal or vulvar cancers, or the work and productivity losses resulting from time spent receiving medical care, morbidity or mortality. Current economic burden estimates would suggest annual direct medical costs associated with the prevention and treatment of anogenital warts and cervical HPV-related disease of at least 4 billion US dollars. This figure would likely rise to at least 5 billion US dollars per year if direct medical costs associated with other disease entities caused by the sexual transmission of HPV were included, with further additions to the economic burden totalling in the billions of dollars if work and productivity losses were incorporated, a research priority for future studies.

Cost effectiveness of losartan in patients with hypertension and LVH: an economic evaluation for Sweden of the LIFE trial.

OBJECTIVE: Evaluate the cost effectiveness of losartan compared with atenolol from a Swedish national health system perspective. DESIGN: The Losartan Intervention For Endpoint reduction in hypertension study (LIFE) was a double-masked, randomized trial of losartan versus atenolol in 9193 patients with essential hypertension and left ventricular hypertrophy (LVH) ascertained by electrocardiography. Losartan reduced the primary composite end point of cardiovascular death, myocardial infarction (MI), or stroke by 13% (P = 0.021) and reduced the risk of stroke by 25% (P = 0.001), despite a comparable degree of blood pressure control. METHODS: Life years gained was estimated by combining the absolute risk reduction in stroke with the life years gained by preventing stroke. Quality-adjusted life years (QALYs) gained was estimated by combining the absolute risk reduction in stroke with the QALYs gained by preventing stroke. QALYs were estimated by weighting life years by health-related quality of life (QoL), as measured with visual analogue scale (VAS) data collected in the trial. Net costs were defined as the total of study medication cost, stroke-related costs, and costs of increased survival. Costs are in 2003 Swedish prices. All costs and effects were discounted at a 3% annual rate. RESULTS: Prevention of a stroke resulted in a gain of 5.7 life years and 4.3 QALYs. As a consequence, losartan treatment resulted in a per patient increase of 0.092 life years [95% confidence interval (CI): 0.038, 0.146] and 0.069 QALYs (95% CI: 0.028, 0.109) as compared with atenolol treatment. Losartan reduced direct stroke-related cost per patient by 1141 euros due to a lower cumulative incidence of stroke for losartan at 5.5 years (4.9%) as compared with atenolol (6.5%) (95% CI of difference: 0.7, 2.5). The reduction in stroke-related cost offset 80% of the added cost of losartan drug therapy. After inclusion of study medication cost, net cost per patient was 289 euros higher for losartan than atenolol. The net cost per QALY gained for losartan was 4188 euros (37,813 SEK), which is well within common Swedish benchmark upper values (200-500,000 SEK) for accepted cost-effective interventions. CONCLUSION: Based on the results from the LIFE trial, treatment with losartan compared with atenolol, in hypertensive patients with LVH, is a cost-effective intervention.

The health and economic burden of genital warts in a set of private health plans in the United States.

We estimated the prevalence of and costs associated with genital warts among privately insured individuals from the perspective of a private health plan in the United States. Health care claims data were derived from a sample of 3,664,686 privately insured individuals. The database was limited to cases of disease for which an insurance claim was generated, with costs reflecting inpatient, outpatient, and pharmacy payments from all sources. We identified 5095 cases of genital warts (1.7 cases per 1000 person-years) billed through the health plans during 2000. The prevalences of and health plan costs associated with genital warts were highest among women aged 20-24 years (6.2 cases and $1692 in costs per 1000 person-years) and men aged 25-29 years (5.0 cases and $1717 in costs per 1000 person-years). On average, individual episodes of care for genital warts involved 3.1 physician visits and incurred costs of $436. These are the first age- and sex-specific estimates of the prevalence and cost of genital warts for a US health plan.