Cost-effectiveness of HPV vaccination in the context of high cervical cancer incidence and low screening coverage

Cost-effectiveness analysis of 9-valent human papillomavirus vaccine combined with screening for cervical cancer in Japan

OBJECTIVE

In Japan, the current coverage rate of human papillomavirus (HPV) vaccination is only 30%, and the rate of biennial cervical screening is 40%. The Japanese Government has attempted to increase the coverage of HPV vaccination and cervical screening. We analyzed the cost-effectiveness of the 9-valent HPV vaccine and cervical screening in Japan.

METHODS

A yearly cycle Markov model with 15 health states was created to evaluate the cost-effectiveness of the 9-valent HPV vaccination and cervical screening in women aged 12-75 years. We considered four scenarios: 30% coverage of vaccination with 40% coverage of biennial screening (Scenario 1 representing the current Japanese situation), 70% (the highest proportion in 2013 in Japan) and 90% coverage of vaccination with 40% coverage of biennial screening (Scenarios 2 and 3, respectively), and 90% coverage of vaccination with 70% coverage of biennial screening (Scenarios 4). The incremental cost-effectiveness ratio (ICER) was calculated as costs per quality-adjusted life year (QALY) based on the perspective of the healthcare payer and compared with the benchmark for willingness to pay in Japan (41 700 USD per QALY). The cumulative morbidity and mortality in each scenario were analyzed using the Markov model.

RESULTS

Compared with Scenario 1, the ICERs of Scenarios 2, 3, and 4 were 5382, 5321, and 8524 USD/QALY, respectively, which were lower than the benchmark for willingness to pay. As the coverage of HPV vaccination and cervical screening increased, the cumulative morbidity and mortality decreased.

CONCLUSION

Increasing the coverage of the 9-valent HPV vaccination and cervical screening is cost-effective in Japan.

Modelling epidemiological and economics processes - the case of cervical cancer

Different types of mathematical models can be used to forecast the development of diseases as well as associated costs and analyse the cost-effectiveness of interventions. The set of models available to assess these parameters, reach from simple independent equations to highly complex agent-based simulations. For many diseases, it is simple to distinguish between infectious diseases and chronic-degenerative diseases. For infectious diseases, dynamic models are most appropriate because they allow for feedback from the number of infected to the number of new infections, while for the latter Markov models are more appropriate since this feedback is not required. However, for some diseases, the aforementioned distinction is not as clear. Cervical cancer, for instance, is caused by a sexually transmitted virus, and therefore falls under the definition of an infectious disease. However, once infected, the condition can progress to a chronic disease. Consequently, cervical cancer could be considered an infectious or a chronic-degenerative disease, depending on the stage of infection. In this paper, we will analyse the applicability of different mathematical models for epidemiological and economic processes focusing on cervical cancer. For this purpose, we will present the basic structure of different models. We will then conduct a literature analysis of the mathematical models used to predict the spread of cervical cancer. Based on these findings we will draw conclusions about which models can be used for which purpose and which disease. We conclude that each type of model has its advantages and disadvantages, but the choice of model type often seems arbitrary. In the case of cervical cancer, homogenous Markov models seem appropriate if a cohort of newly infected is followed for a shorter period, for instance, to assess the impact of screening programs. For long-term consequences, such as the impact of a vaccination program, a feedback loop from former infections to the future likelihood of infections is required. This can be done using system dynamics or inhomogeneous Markov models. Discrete event or agent-based simulations can be used in the case of cervical cancer when small cohorts or specific characteristics of individuals are required. However, these models require more effort than Markov or System Dynamics models.

Fine-grained mathematical modeling for cost-effectiveness evaluation of public health policies for cervical cancer, with application to a Colombian case study

BACKGROUND

Cervical cancer (CC) is globally ranked fourth in terms of incidence and mortality among women. Vaccination against Human Papillomavirus (HPV) and screening programs can significantly reduce CC mortality rates. Hence, executing cost-effective public health policies for prevention and surveillance is crucial. However, defining policies that make the best use of the available resources is not easy, as it requires predicting the long-term costs and results of interventions on a changing population. Since the simpler task of predicting the results of public health policies is difficult, devising those that make the best usage of available resources is an arduous challenge for decision-makers.

METHODS

This paper proposes a fine-grained epidemiological simulation model based on differential equations, to effectively predict the costs and effectiveness of CC public health policies that include vaccination and screening. The model represents population dynamics, HPV transmission within the population, likelihood of infection clearance, virus-induced appearance of precancerous lesions and eventually CC, as well as immunity gained with vaccination and early detection with screening.

RESULTS

We offer a compartmentalized modeling approach that separates population, epidemics, and intervention concerns. We instantiate models with actual data from a Colombian case study and analyze their results to show how our modeling approach can support CEA studies. Moreover, we implement models in an open-source software tool to simultaneously define and evaluate multiple policies. With the support of the tool, we analyze 54 policies within a 30-year time horizon and use as a comparator the CC policy that has been used until recently. We identify 8 dominant policies, the best one with an ICER of 6.3 million COP (Colombian Pesos) per averted DALY. We also validate the modeling approach against the available population and HPV epidemic data. The effects of uncertainty in the values of key parameters (discount rate, sensitivity of screening tests) is evaluated through one-way sensitivity analysis.

CONCLUSIONS

Our modeling approach can provide valuable support for healthcare decision-makers. The implementation into an automated tool allows customizing the analysis with country-specific data, flexibly defining public health policies to be evaluated, and conducting disaggregate analyses of their cost and effectiveness.

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.

The Lifetime Cost Estimation of Human Papillomavirus-related Diseases in China: A Modeling Study

OBJECTIVES

To estimate the lifetime treatment costs of patients with human papillomavirus (HPV) infection-related diseases in China and to provide cost estimates for the economic evaluation of HPV intervention strategies.

METHODS

We extracted real-world hospital data from 2012 to 2019 and screened for subjects who met the criteria of clinical diagnosis of HPV-related diseases to obtain country-specific inputs into a Markov decision model. The model simulated lifetime treatment costs for HPV from the perspective of a national payer. A 5% discount rate was applied. Costs were converted and inflated to 2020 US dollars (USD).

RESULTS

Using 2021 as the base year, the lifetime costs per patient for carcinoma in situ, local metastasis, and distant metastasis cervical cancer are $24,208 (95%CI: 18,793-30,897), $19,562 (95%CI: 14,456-25,567), and $17,599 (95%CI: 10,604-25,807), respectively. For carcinoma in situ, local metastasis, and distant metastasis vaginal cancer, the lifetime costs are $17,593 (95%CI: 14,962-23,596), $17,120 (95%CI: 13,215-22,417), and $22,411 (95%CI: 12,172-22,249), respectively. The base-case lifetime cost per patient for different stages of vulvar cancer/penile cancer/anal cancer/oral cancer/oropharyngeal cancer/laryngeal cancer falls within $17,120-$58,236.

CONCLUSIONS

Using real-world data, we calculated lifetime treatment costs of HPV-related cancer in China and found that the lifetime cost for patients exceeded $17,000 for various stages of disease. The national burden of HPV-related disease could be significantly reduced by eliminating HPV infection.

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.

Cervical Cancer Screening Programs in Europe: The Transition Towards HPV Vaccination and Population-Based HPV Testing

Cervical cancer is the fourth most frequently occurring cancer in women around the world and can affect them during their reproductive years. Since the development of the Papanicolaou (Pap) test, screening has been essential in identifying cervical cancer at a treatable stage. With the identification of the human papillomavirus (HPV) as the causative agent of essentially all cervical cancer cases, HPV molecular screening tests and HPV vaccines for primary prevention against the virus have been developed. Accordingly, comparative studies were designed to assess the performance of cervical cancer screening methods in order to devise the best screening strategy possible. This review critically assesses the current cervical cancer screening methods as well as the implementation of HPV vaccination in Europe. The most recent European Guidelines and recommendations for organized population-based programs with HPV testing as the primary screening method are also presented. Lastly, the current landscape of cervical cancer screening programs is assessed for both European Union member states and some associated countries, in regard to the transition towards population-based screening programs with primary HPV testing.

Evaluation of HPV DNA positivity in colorectal cancer patients in Kerman, Southeast Iran

Background:

The HPV virus is known to be oncogenic and associations with many cancers has been proven. Although many studies have been conducted on the possible relationship with colorectal cancer (CRC), a definitive role of the virus has yet to be identified.

Method:

In this cross-sectional study, the frequency of HPV positivity in CRC samples in Kerman was assessed in 84 cases with a mean age of 47.7 ± 12.5 years over two years. Qualitative real time PCR was performed using general primers for the L1 region of HPV DNA.

Results:

Out of 84 CRC samples, 19 (22.6%), proved positive for HPV DNA. Genotyping of positive samples showed all of these to be of high risk HPV type. Prevalence of HPV infection appears to depend geographic region, life style, diet and other factors.

Conclusion:

In our location frequency of CRC is low, and this limited the sample size for evaluation of HPV DNA. The most prevalent types were HPV types 51 and 56. While HPV infection may play an important role in colorectal carcinogenesis, this needs to be assessed in future studies.