Economic Evaluations of HPV Vaccination in Targeted Regions of Low- and Middle-Income Countries: A Systematic Review of Modelling Studies

Background

In countries with limited resources, a targeted HPV vaccination strategy by focusing in selected regions is preferable to be implemented than a nationwide vaccination strategy.

Objective

This study aimed to review articles on economic evaluations of HPV vaccination in countries over the world that applied targeted vaccination strategies.

Methods

Approximately 1769 articles were obtained from two databases (1242 and 527 articles from PubMed and ProQuest, respectively). The inclusion criteria in this systematic review were studies about full economic evaluations of HPV vaccination in targeted area or sub-national level and written in English. Full-text screening was applied to evaluate the eligibility. Final articles obtained were referred to the Consolidated Health Economic Evaluation Reporting Standard (CHEERS) checklist. Finally, we included only 4 articles that met all inclusion and exclusion criteria.

Results

Included studies in this review focused in different targeted regions, such as Punjab State in India, Vientiane in Lao PDR, Southern Vietnam in Vietnam, and Brazilian Amazon in Brazil. From 24 criteria in the CHEERS checklist, all included studies could meet 21 criteria (87.5%). All included studies in this review applied modeling approaches, which can estimate the number of cases and treatment costs averted. Applying various settings, the results of this study showed that HPV vaccination could potentially reduce the number of cervical cancer cases by 20–72%. Taking cervical cancer screening into account, this study showed that targeted HPV vaccination was cost-effective or even cost-saving.

Conclusion

Implementation of HPV vaccination in sub-national level as the initial step before nationwide vaccination is more favorable to be implemented in countries with limited budget.

Inclusion of the value of herd immunity in economic evaluations of vaccines. A systematic review of methods used

OBJECTIVE

The objectives of this review were to identify vaccine economic evaluations that include herd immunity and describe the methodological approaches used.

METHODS

We used Kim and Goldie's search strategy from a systematic review (1976-2007) of modelling approaches used in vaccine economic evaluations and additionally searched PubMed/MEDLINE and Embase for 2007-2015. Studies were classified according to modelling approach used. Methods for estimating herd immunity effects were described, in particular for the static models.

RESULTS

We identified 625 economic evaluations of vaccines against human-transmissible diseases from 1976 to 2015. Of these, 172 (28%) included herd immunity. While 4% of studies included herd immunity in 2001, 53% of those published in 2015 did this. Pneumococcal, human papilloma and rotavirus vaccines represented the majority of studies (63%) considering herd immunity. Ninety-five of the 172 studies utilised a static model, 59 applied a dynamic model, eight a hybrid model and ten did not clearly state which method was used. Relatively crude methods and assumptions were used in the majority of the static model studies.

CONCLUSION

The proportion of economic evaluations using a dynamic model has increased in recent years. However, 55% of the included studies used a static model for estimating herd immunity. Values from a static model can only be considered reliable if high quality surveillance data are incorporated into the analysis. Without this, the results are questionable and they should only be included in sensitivity analysis.

REVIEWING TRANSFERABILITY IN ECONOMIC EVALUATIONS ORIGINATING FROM EASTERN EUROPE

Objectives: The aim of this study is to analyze the quality and transferability issues reported in published peer-reviewed English-language economic evaluations based in healthcare settings of the Central and Eastern European (CEE) and former Soviet countries.

Methods: A systematic search of economic evaluations of healthcare interventions was performed for Armenia, Azerbaijan, Belarus, Bulgaria, Estonia, Georgia, Turkmenistan, Kazakhstan, Lithuania, the former Yugoslav Republic of Macedonia, Republic of Moldova, Romania, the Russian Federation, Serbia, Slovenia, and Ukraine. The included studies were assessed according to their characteristics, quality (using Drummond's checklist), use of local data, and the transferability of inputs and results, if addressed.

Results: Most of the thirty-four economic evaluations identified were conducted from a healthcare or payer perspective (74 percent), with 47 percent of studies focusing on infectious diseases. The least frequently and transparently addressed parameters were the items’ stated perspectives, relevant costs included, accurately measured costs in appropriate units, outcomes and costs credibly valued, and uncertainties addressed. Local data were often used to assess unit costs, baseline risk, and resource usage, while jurisdiction-specific utilities were included in only one study. Only 32 percent of relevant studies discussed the limitations of using foreign data, and 36 percent of studies discussed the transferability of their own study results to other jurisdictions.

Conclusions: Transferability of the results is not sufficiently discussed in published economic evaluations. To simplify the transferability of studies to other jurisdictions, the following should be comprehensively addressed: uncertainty, impact of influential parameters, and data transferability. The transparency of reporting should be improved.

How university students view human papillomavirus (HPV) vaccination: A cross-sectional study in Jinan, China

The acceptability of HPV vaccination among university students in China is not well understood. Our study was of cross-sectional study design. We collected a questionnaire about socio-demographic characteristics, knowledge of, attitude toward and acceptability of HPV vaccination. A total of 351 students were included in data analyses, among whom 47.6% were males and 70.0% aged 19-21. Only 10.3% had previously heard of HPV and 5.4% HPV vaccine. Male and female students were equally likely to accept HPV vaccine (71.8 vs 69.4%, p = 0.634) and recommend it to sexual partners (73.1 vs 76.7%, p = 0.441). The great majority of students could only afford RMB 300 (USD 50) or less for HPV vaccination. HPV vaccination acceptance was associated with being in year-one (Adjusted odds ratio (AOR)  = 3.78, 95% confidence interval (CI): 2.12-6.75), being from a key university (AOR = 1.88, 95%CI: 1.07-3.31), having heard of HPV-related morbidities (AOR = 1.88, 95% CI: 1.05-3.35), being concerned about HPV-related morbidities (AOR = 2.23, 95% CI: 1.16-4.27) and believing the vaccine should be given before first sexual contact (AOR = 2.44, 95% CI: 1.38-4.29). Female students were more likely to anticipate a late uptake of HPV vaccination (p = 0.002). The relatively lower levels of HPV knowledge but higher levels of vaccine acceptance among undergraduates highlighted the need for education on the roles of sexual behaviors in HPV transmission.

The epidemiological and economic impact of a quadrivalent human papillomavirus (hpv) vaccine in Estonia

BACKGROUND

This analysis assessed the epidemiological and economic impact of quadrivalent human papillomavirus (HPV4: 6/11/16/18) vaccination in Estonia.

METHODS

A dynamic transmission model was used to assess the epidemiological and economic impact of the routine vaccination of 12-year-old girls with a HPV4 vaccine in preventing cervical cancer, cervical intraepithelial neoplasia (CIN) grades 1, 2 and 3 and genital warts.

RESULTS

The model projected that at year 100, HPV4 vaccination would lead to a reduction of HPV 16/18 related cervical cancer incidence and deaths by over 97% and the incidence of HPV 6/11 related genital warts among Estonian women and men by over 94% and 81%, respectively. The incremental cost-effectiveness ratio of the HPV4 vaccination strategy was € 4,889 per QALY gained over a time horizon of 100 years.

CONCLUSIONS

Routine vaccination of 12-year-old girls with HPV4 vaccine appears to be cost-effective in Estonia, in addition to providing both short term and long term health gains.

Cost-effectiveness of human papillomavirus vaccination in low and middle income countries: a systematic review

The World Health Organization recommends establishing that human papillomavirus vaccination is cost-effective before vaccine introduction. We searched Pubmed, Embase and the Cochrane Library to 1 April 2012 for economic evaluations of human papillomavirus vaccination in low and middle income countries. We found 25 articles, but almost all low income countries and many middle income countries lacked country-specific studies. Methods, assumptions and consequently results varied widely, even for studies conducted for the same country. Despite the heterogeneity, most studies conclude that vaccination is likely to be cost-effective and possibly even cost saving, particularly in settings without organized cervical screening programmes. However, study uncertainty could be reduced by clarity about vaccine prices and vaccine delivery costs. The review supports extending vaccination to low income settings where vaccine prices are competitive, donor funding is available, cervical cancer burden is high and screening options are limited.

Economic evaluation of vaccination: capturing the full benefits, with an application to human papillomavirus

Vaccination has been among the greatest contributors to the past century's dramatic improvements in health and life expectancy. Recent advances in vaccinology have resulted in new vaccines that will likely lead to substantial future health gains. However, the high cost of these new vaccines, such as the human papillomavirus (HPV) vaccine, poses an obstacle to their widespread adoption in many countries. Economic evaluation can help to determine if investment in vaccine introduction is worthwhile. However, existing economic evaluations usually focus on a narrow set of vaccination-mediated benefits-most notably avoided medical-care costs-and fail to account for several categories of potentially important gains. We consider three sources of such benefit and discuss them with respect to HPV vaccination: (i) outcome-related productivity gains, (ii) behaviour-related productivity gains, and (iii) externalities. We also highlight that HPV vaccination protects against more than just cervical cancer and that these other health gains should be taken into account. Failing to account for these broader benefits of HPV vaccination could result in substantial underestimation of the value of HPV vaccination, thereby leading to ill-founded decisions regarding its introduction into national immunization programmes.

Healthcare spending in the case of a HPV16/18 population-wide vaccination programme

BACKGROUND

The policy of population-wide human papillomavirus (HPV) vaccination has been debated as the introduction of such a programme in a low-resource country faces the risk of insufficient cost-effectiveness.

OBJECTIVES

To assess the potential healthcare spending changes after the introduction of a HPV16/18 population-wide vaccination programme in Lithuania.

STUDY DESIGN

For a cost-effectiveness analysis, we used mathematical simulation and epidemiological data modelling based on a Lithuanian female population. We performed comparative analysis of an annual 12-year-old girls population-wide vaccination programme combined with cervical cancer screening programme compared to the screening programme strategy only.

RESULTS

HPV vaccination would gain an average of 35.6 life years per death avoided or up to 284.8 thousand life years would be gained over 90 years in total. The programme costs would be 2932.58 EUR per life year gained. All costs associated with the introduction of the vaccination programme could be recovered in 48 years. The HPV vaccination programme in Lithuania has the potential to generate up to 40.07 million EUR of economic returns annually compared with the current practice of the cervical screening alone.

CONCLUSIONS

In Lithuania the HPV16/18 vaccination programme would be economically effective only in the long term. The investment costs of HPV16/18 vaccination have the potential to be recovered.

Next Generation Cancer Protection: The Bivalent HPV Vaccine for Females

Nearly a half a million women throughout the world develop cervical cancer every year Parkin and Bray ("Chapter 2. The burden of HPVrelated cancers," Vaccine, vol. 24, no. 3, pp. S11-S25, 2006); 80% of these women are in countries without a quality-assured cytology screening program. It is in this setting that Cervarix could reduce the incidence of cervical cancer to about 9.5/100,000 women. New evidence indicates that this might be able to be accomplished with a single dose of Cervarix, a great advantage to public health implementation programs Kreimer et al. ("Proof-of-principle evaluation of the efficacy of fewer than three doses of a bivalent HPV16/18 vaccine, The Journal of the National Cancer Institute, vol. 103, no. 19, pp. 1444-1451, 2011). In countries with screening programs, adenocarcinoma is the most difficult to detect and treat with later-stage presentation and higher mortality Smith et al. ("The rising incidence of adenocarcinoma relative to squamous cell carcinoma of the uterine cervix in the United States-a 24-year population-based study," Gynecologic Oncology, vol. 78, no. 2, pp. 97-105, 2000) and Gunnell et al. ("A longitudinal Swedish study on screening for squamous cell carcinoma and adenocarcinoma: evidence of effectiveness and overtreatment," Cancer Epidemiology Biomarkers and Prevention, vol. 16, no. 12, pp. 2641-2648, 2007). With additional cross-protection to HPV 31, 33, and 45 and protection against HPV 16 and 18 lasting at least 9.4 years, Cervarix may reduce adenocarcinomas in screened populations by more than 90%. This paper will detail the evidence about the efficacy, immunogenicity, and safety of Cervarix in the studied populations contrasting public health goals with individual health options.