Present and future of cervical cancer prevention in Spain: a cost-effectiveness analysis

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.

Is the HPV-test more cost-effective than cytology in cervical cancer screening? An economic analysis from a middle-income country

OBJECTIVE

To report a modelling study using local health care costs and epidemiological inputs from a population-based program to access the cost-effectiveness of adopting hrHPV test.

METHODS

A cost-effectiveness analysis based on a microsimulation dynamic Markov model. Data and costs were based on data from the local setting and literature review. The setting was Indaiatuba, Brazil, that has adopted the hrHPV test in place of cytology since 2017. After calibrating the model, one million women were simulated in hypothetical cohorts. Three strategies were tested: cytology to women aged 25 to 64 every three years; hrHPV test to women 25-64 every five years; cytology to women 25-29 years every three years and hrHPV test to women 30-64 every five years (hybrid strategy). Outcomes were Quality-adjusted life-years (QALY) and Incremental Cost-Effectiveness Ratio (ICER).

RESULTS

The hrHPV testing and the hybrid strategy were the dominant strategies. Costs were lower and provided a more effective option at a negative incremental ratio of US$ 37.87 for the hybrid strategy, and negative US$ 6.16 for the HPV strategy per QALY gained. Reduction on treatment costs would influence a decrease in ICER, and an increase in the costs of the hrHPV test would increase ICER.

CONCLUSIONS

Using population-based data, the switch from cytology to hrHPV testing in the cervical cancer screening program of Indaiatuba is less costly and cost-effective than the old cytology program.

Methodologies of Primary HPV Testing Currently Applied for Cervical Cancer Screening

The human papillomavirus is one of the most common sexually transmitted viruses, and an infection from this virus may become persistent, leading to diseases such as cervical cancer. In the past, cytology-based methods such as the Papanicolaou (Pap) test were imperative to identify the disease at a stage where it can be treated. However, since the 1980s where the etiological association of HPV and cervical cancer was identified, new tests began emerging directed towards identifying the virus. Furthermore, as the biology of HPV along with the relationships with its host are elucidated, these tests and treatments further advance. Recently in Europe, there is a movement towards the implementation of HPV testing methodologies in national screening programs to precede cytological testing. These screening strategies are recommended by the European guidelines and the World Health Organization. This review presents the current HPV testing methodologies, their application in organized population-based cervical cancer screening programs based on the most recent European guidelines, and their implementation status in countries in Europe.

Online Cost-Effectiveness ANalysis (OCEAN): a user-friendly interface to conduct cost-effectiveness analyses for cervical cancer

Background

Most cost-effectiveness analyses in the context of cervical cancer prevention involve the use of mathematical models to simulate HPV infection, cervical disease and prevention strategies. However, it is common for professionals who would need to perform these analyses to not be familiar with the models. This work introduces the Online Cost-Effectiveness ANalysis tool, featuring an easy-to-use web interface providing health professionals, researchers and decision makers involved in cervical cancer prevention programmes with a useful instrument to conduct complex cost-effectiveness analyses, which are becoming an essential tool as an approach for supporting decision-making that involves important trade-offs.

Results

The users can run cost-effectiveness evaluations of cervical cancer prevention strategies without deep knowledge of the underlying mathematical model or any programming language, obtaining the most relevant costs and health outcomes in a user-friendly format. The results provided by the tool are consistent with the existing literature.

Conclusions

Having such a tool will be an asset to the cervical cancer prevention community, providing researchers with an easy-to-use instrument to conduct cost-effectiveness analyses.

Cervical cancer prevention in Morocco: a model-based cost-effectiveness analysis

Objective: Cervical cancer is a huge public health issue in Morocco which represents the second most frequent and fatal cancer among women. Countries that have not yet introduced the HPV vaccine could benefit greatly, but before implementation it is necessary to perform country-specific economic assessments that include current screening practices. Methods: A Markov model was developed to simulate the natural history of HPV and cervical cancer so as to calculate the long-term health benefits and costs of HPV vaccination and current screening by visual inspection with acetic acid (VIA). Starting from a previous transition probability matrix used for a model from Spain, the present model was calibrated to cervical cancer incidence from Morocco. Cost survey data was used to estimate the cost of screening and clinical procedures from the public healthcare perspective. Incremental cost-effectiveness ratios were calculated as 2018US$ per additional year of life saved (YLS) and both costs and health outcomes were discounted at 3%. Results: The expected reduction in lifetime risk of cervical cancer for current screening would be 14% at a cost of US$551/YLS compared with no intervention, assuming VIA every 3 years in women aged 30-49 at 10% coverage. HPV vaccination of pre-adolescent girls at 70% coverage would reduce the lifetime risk of cervical cancer by 62% at a cost of US$1,150/YLS, compared with no intervention. When implementing HPV vaccination in combination with current screening, vaccination would be dominated, and the combined strategy would provide a 69% reduction at a cost of US$2,843/YLS, compared with screening alone. Current screening would be dominated by vaccination when screening coverage is higher than 15%, whereas the combined strategy rapidly exceeds US$4,000/YLS. Conclusions: HPV vaccination could be highly effective and cost-effective in Morocco. Current screening would be good value for money compared with no intervention, but scaling-up screening coverage would make it inefficient compared with vaccination.

Estimating the epidemiological impact and cost-effectiveness profile of a nonavalent HPV vaccine in Spain

Human papillomavirus (HPV) is one of the main causes of infection-related cancer. The bivalent vaccine (2vHPV) (16/18) and quadrivalent (6/11/16/18) HPV vaccine (4vHPV) have been included in the Spanish vaccination calendar since 2007. The new nonavalent HPV vaccine (9vHPV), approved in Europe in 2015, includes nine HPV types 6/11/16/18/31/33/45/52/58 and has been available in Spain since May 2017. Our study aims to estimate the epidemiological impact and the cost-effectiveness of a girls-only and a gender-neutral vaccination program with 9vHPV compared to the current vaccination program in Spain. A dynamic transmission model simulating the natural history of HPV infections was calibrated to the Spanish setting and applied to estimate costs and quality-adjusted life years (QALYs) associated with vaccination strategies using a payer perspective and a 100-year time horizon. A girls-only vaccination strategy at age 12 years with 9vHPV was found to be a cost-effective strategy compared with 4vHPV (incremental cost-effectiveness ratio (ICER) of €7,718 per QALY). Compared with girls-only vaccination with 4vHPV, gender-neutral vaccination with 9vHPV was associated with further reductions of up to 28.5% in the incidence of cervical intraepithelial neoplasia (CIN) 2/3 and 17.1% in the incidence of cervical cancer, as well as with a 14.0% reduction in cervical cancer mortality. Furthermore, a gender-neutral vaccination program with 9vHPV could potentially be cost-effective considering some parameters as head and neck protection or discount rates, leading to a reduction in the burden of HPV-related diseases in both sexes in the Spanish population.

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.

Moving towards an organized cervical cancer screening: costs and impact

Background

HPV screening has been shown to be more cost-effective than cytology screening under most scenarios. Furthermore, it should be offered only in organized programmes with good quality assurance mechanisms. This study analyses the comparative cost of the current policy of opportunistic cytology screening vs. a hypothetical organized programme based on primary HPV screening.

Methods

Total cervical cancer expenditure was defined as the sum of three cost elements: (i) direct (medical and non-medical) costs, obtained from a calibrated Markov model of the natural history of HPV and cervical cancer; (ii) programmatic costs, estimated based on other organized screening programmes; and (iii) indirect costs, extrapolated from previously published data.

Results

Organized HPV screening at 5-year intervals costs consistently less across all coverage levels than opportunistic cytology screening at 3-year intervals. The current annual direct medical cost to the public health system of the opportunistic cytology at 40% coverage is estimated at €33.2 per woman screened aged 25-64. Under an organized programme of primary HPV screening at 70% coverage, the cost is estimated to be €18.4 per woman screened aged 25-64.

Conclusion

Our study concludes that the economic resources currently devoted to providing opportunistic cytology screening to 40% of the target population at 3-year intervals could be more effectively used to screen 70% of the target population at 5-year intervals by switching to an organized programme based on primary HPV screening. This finding is of relevance to other European countries or regions with similar screening policies and health infrastructures.

Impact of model calibration on cost-effectiveness analysis of cervical cancer prevention

Markov chain models are commonly used to simulate the natural history of human papillomavirus infection and subsequent cervical lesions with the aim of predicting future benefits of health interventions. Developing and calibrating these models entails making a number of critical decisions that will influence the ability of the model to reflect real conditions and predict future situations. Accuracy of selected inputs and calibration procedures are two of the crucial aspects for model performance and understanding their influence is essential, especially when involves policy decisions. The aim of this work is to assess the health and economic impact on cervical cancer prevention strategies currently under discussion according to the most common methods of model calibration combined with different accuracy degree of initial inputs. Model results show large differences on the goodness of fit and cost-effectiveness outcomes depending on the calibration approach used, and these variations may affect health policy decisions. Our findings strengthen the importance of obtaining good calibrated probability matrices to get reliable health and cost outcomes, and are directly generalizable to any cost-effectiveness analysis based on Markov chain models.

Cost-effectiveness of strategies to increase screening coverage for cervical cancer in Spain: the CRIVERVA study

BACKGROUND

The aim of the study is to carry out a cost-effectiveness analysis of three different interventions to promote the uptake of screening for cervical cancer in general practice in the county of Valles Occidental, Barcelona, Spain.

METHODS

Women aged from 30 to 70 years (n = 15,965) were asked to attend a general practice to be screened. They were randomly allocated to one of four groups: no intervention group (NIG); one group where women received an invitation letter to participate in the screening (IG1); one group where women received an invitation letter and informative leaflet (IG2); and one group where women received an invitation letter, an informative leaflet and a phone call reminder (IG3). Clinical effectiveness was measured as the percentage increase in screening coverage. A cost-effectiveness analysis was performed from the perspective of the public health system with a time horizon of three to five years - the duration of the randomised controlled clinical trial. In addition, a deterministic sensitivity analysis was performed. Results are presented according to different age groups.

RESULTS

The incremental cost-effectiveness ratio (ICER) for the most cost-effective intervention, IG1, compared with opportunistic screening was € 2.78 per 1% increase in the screening coverage. The age interval with the worst results in terms of efficiency was women aged < 40 years.

CONCLUSIONS

In a population like Catalonia, with around 2 million women aged 30 to 70 years and assuming that 40% of these women were not attending general practice to be screened for cervical cancer, the implementation of an intervention to increase screening coverage which consists of sending a letter would cost on average less than € 490 for every 1000 women.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01373723 .