Cost-effectiveness analysis of AS04-adjuvanted human papillomavirus 16/18 vaccine compared with human papillomavirus 6/11/16/18 vaccine in the Philippines, with the new 2-dose schedule

Current Status of Human Papillomavirus Infection and Cervical Cancer in the Philippines

Cervical cancer is estimated to cause 341,831 deaths each year, with 9 of 10 deaths occurring in developing countries. Over the past decade, there has been a significant increase in cervical cancer incidence among women in the Philippines. Persistent infection with high-risk human papillomavirus (HPV) is the well-established necessary cause of cervical cancer. Based on limited studies conducted in the Philippines, the prevalence of infection with any HPV genotype was 93.8% for cervical squamous cell carcinoma and 90.9% for cervical adenocarcinomas. HPV types 16 and 18 were the most common HPV genotypes among Filipino patients with cervical cancer. On the other hand, the incidence of HPV infection among Filipino women with normal cervices was 9.2%. The World Health Organization has launched a global agenda of eliminating HPV infection by 2030. One of its key milestones is to vaccinate 90% of girls with the HPV vaccine by 15 years. However, the HPV vaccination rate among Filipino women remains to be unsatisfactory. HPV vaccination has only been included in the Philippine Department of Health's community-based National Immunization Program in 2015. Despite these efforts, the Philippines currently ranks last on HPV program coverage among low-middle income countries, with coverage of only 23% of the target female population for the first dose and 5% for the final dose. The principal reason for the non-acceptance of HPV vaccines was the perceived high cost of vaccination. The low utilization of available cervical cancer screening tests such as Pap smear and visual inspection with acetic acid hampered the Philippines' control and prevention of HPV infection and cervical cancer. Among those diagnosed with cervical cancer in the Philippines, only an estimated 50% to 60% receive some form of treatment. To this end, we summarize the burden of HPV infection and cervical cancer on Filipinos and the risk factors associated with the disease. We present the current screening, diagnostics, treatment, and prevention of HPV-related diseases in the Philippines. Lastly, we also propose solutions on how each building block in health systems can be improved to eliminate HPV infection and reduce the burden of cervical cancer in the Philippines.

Estimating the EQ-5D-5L value set for the Philippines

Background

The Philippines has recommended the use of Quality-Adjusted Life Years (QALYs) in government health technology assessments (HTA). We aimed to develop a value set for the EQ-5D-5L based on health preferences of the healthy general adult population in the Philippines.

Methods

Healthy, literate adults were recruited from the Philippine general population with quota targets based on age, sex, administrative region, type of residence, education, income, and ethnolinguistic groups. Each participant’s preference was elicited by completing Composite Time Trade-Off (C-TTO) and Discrete Choice Experiment (DCE) tasks. Tasks were computer-assisted using the EuroQol Valuation Technology 2.0. To estimate the value set, we explored 20- and 8-parameter models that either use c-TTO-only data or both c-TTO and DCE (also called hybrid models). Final model choice was guided by principles of monotonicity, out-of-sample likelihood, model fit, and parsimony.

Results

We recruited 1000 respondents with demographic characteristics that approximate the general population such as 49.6% Female, 82% Roman Catholic, 40% in urban areas, and 55% finished high school. None of the 20-parameter models demonstrated monotonicity (logical worsening of coefficients with increasing severity). From the 8-parameter models, the homoscedastic TTO-only model exhibited the best fit. From this model, mobility and pain/ discomfort had the highest effect on utilities.

Conclusion

The selected model for representing the Philippine general population preferences for EQ-5D-5L health states was an 8-parameter homoscedastic TTO-only model. This value set is recommended for use in QALY calculations in support of HTA-informed coverage decisions in the Philippines.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11136-022-03143-w.

Inclusion of Additional Unintended Consequences in Economic Evaluation: A Systematic Review of Immunization and Tuberculosis Cost-Effectiveness Analyses

OBJECTIVE

Our objective was to review economic evaluations of immunization and tuberculosis to determine the extent to which additional unintended consequences were taken into account in the analysis and to describe the methodological approaches used to estimate these, where possible.

METHODS

We sourced the vaccine economic evaluations from a previous systematic review by Nymark et al. (2009-2015) and searched PubMed/MEDLINE and Embase from 2015 to 2019 using the same search strategy. For tuberculosis economic evaluations, we extracted studies from 2009 to 2019 that were published in a previous review by Siapka et al. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance. Studies were classified according to the categories and subcategories (e.g., herd immunity, non-specific effects, and labor productivity) defined in a framework identifying additional unintended consequences by Nymark and Vassall. Where possible, methods for estimating the additional unintended consequences categories and subcategories were described. We evaluated the reporting quality of included studies according to the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) extraction guideline.

RESULTS

We identified 177 vaccine cost-effectiveness analyses (CEAs) between 2009 and 2019 that met the inclusion criteria. Of these, 98 included unintended consequences. Of the total 98 CEAs, overall health consequence categories were included 73 times; biological categories: herd immunity 43 times; pathogen response: resistance 15 times; and cross-protection 15 times. For health consequences pertaining to the supply-side (health systems) categories, side effects were included five times. On the nonhealth demand side (intrahousehold), labor productivity was included 60 times. We identified 29 tuberculosis CEAs from 2009 to 2019 that met the inclusion criteria. Of these, six articles included labor productivity, four included indirect transmission effects, and one included resistance. Between 2009 and 2019, only 34% of tuberculosis CEAs included additional unintended consequences, compared with 55% of vaccine CEAs.

CONCLUSIONS

The inclusion of additional unintended consequences in economic evaluations of immunization and tuberculosis continues to be limited. Additional unintended consequences of economic benefits, such as those examined in this review and especially those that occur outside the health system, offer valuable information to analysts. Further work on appropriate ways to value these additional unintended consequences is still warranted.

Economic evaluation of human papillomavirus vaccination in the Global South: a systematic review

OBJECTIVES

Many reviews have been conducted on the economic evaluation of the HPV vaccine in global north countries. But there is a dearth of such reviews in the Global South countries. Hence, this systematic review aims to summarize studies done in these countries.

METHODS

Four databases PubMed, Embase, Cochrane Library, and Google Scholar from 2009 to 2019 were searched for economic evaluations on HPV vaccination in the Global South countries. PRISMA guidelines were followed to include full-text articles. 40 original articles were shortlisted for full-text review.

RESULTS

Studies had varied models, assumptions, and results according to different scenarios. Most studies concluded HPV vaccination to be cost-effective under varied scenarios and vaccine cost was the most influential parameter affecting the sensitivity analyses, consequently incremental cost-effectiveness ratio. A wide range in the cost-effectiveness ratio was observed in the included studies due to different study settings, populations, and inconsistencies in modeling practices (variations in methodological approaches).

CONCLUSIONS

This review suggests the introduction of HPV vaccination alone or in combination with screening according to different countries. The price of the vaccine should be economical and funds for the vaccine should be provided by public sector firms.