Cost-benefit analysis of Haemophilus influenzae type b vaccination in children in Spain

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.

The use of modeling in the economic evaluation of vaccines

As a consequence of the increased role of pharmacoeconomics in policy-making, economic evaluations are performed at more and more early stages in the development of a therapeutic. This implies the development of models to assess the future impact of an intervention and to account for the level of uncertainty in the associated parameters. This also applies for economic evaluations of vaccines, where not only progression of disease and associated costs are important, but the transmission of the causing agent in the target population also has to be modelled. In this review, we provide an overview of the models that have been used in recent publications on the pharmacoeconomics of vaccines and go deeper into some of the methodological issues associated with the use of models in the economic evaluation of vaccines.

Transferability indices for health economic evaluations: methods and applications

In this paper, we have elaborated an index in two phases to measure the degree of transferability of the results of the economic evaluation of health technologies. In the first phase, we have considered the objective factors (critical and non-critical) to derive a general transferability index, which can be used to measure this internal property of the studies of economic evaluation applied to health technologies. In the second phase, with a more specific index, we have measured the degree of applicability of the results of a given study to a different setting. Both indices have been combined (arithmetic and geometric mean) to obtain a global transferability index. We have applied the global index to a sample of 27 Spanish studies on infectious diseases. We have obtained an average value for the index of 0.54, quite far from the maximum theoretical value of 1. We also found that 11 studies lacked some critical factor and were directly deemed as not transferable.

Cost-benefit analysis of haemophilus influenzae type B immunization in Korea

An economic evaluation of Haemophilus influenzae type b (Hib) immunization was conducted to examine whether Hib immunization should be included in Korea's national immunization program. The costs and benefits included direct and indirect values and an estimation of the economic efficiency. We determined that a universal Hib immunization program in Korea would prevent 17 deaths and 280 invasive Hib cases. When we assumed the one Hib immunization cost as 26,000 won, the national Hib immunization would cost 34.6 billion won. Costs for various Hib diseases were estimated at 26.8 billion won (11.8 billion won from direct costs and 14.9 billion won from indirect costs). A benefit-cost ratio of 0.77 showed that the economic efficiency of the integration of Hib immunization in Korea is low because of the low incidence rate of Hib disease and high price of vaccine. However, if the Hib immunization cost decrease to less than 20,000 won, a benefit-cost ratio increase to 1.0 and above, integrating Hib immunization into the national immunization program with economic efficiency can be considered.

Economic evaluation of Haemophilus influenzae type b vaccination in Moscow, Russian Federation

OBJECTIVE

To estimate the cost-effectiveness of providing Haemophilus influenzae type b (Hib) vaccine to children in Moscow in routine immunization services.

METHODS

The incidence of Hib meningitis among children aged <5 years in Moscow was obtained from a prospective surveillance study undertaken during October 1999-September 2001, with treatment cost data collected for all cases. Sequelae in surviving children were assessed in December 2002. The costs of Hib vaccination in Moscow were estimated assuming a vaccine price of US dollar 5 per dose and the same four-dose schedule and 97% coverage as for diphtheria-tetanus-pertussis vaccine. The most uncertain variables were varied in a sensitivity analysis.

RESULTS

The annual incidence of Hib meningitis was 5.7 per 100,000 children <5 years. The average treatment cost for an acute Hib meningitis case was US dollar 1296. For a patient with sequelae, the average additional lifetime discounted treatment cost was US dollar 15,820. The total annual cost of Hib vaccination of infants in Moscow was estimated as US dollar 1.5 million per year. In the base case analysis, the cost-effectiveness ratios amount to US dollar 77,503 per Hib meningitis case averted and US dollar 10,842 per discounted disability adjusted life year averted. The break-even vaccine price, where the annual vaccination costs equal annual treatment costs averted, is only US dollar 0.04 per dose in the base case scenario. If discounted indirect costs are included, the break-even vaccine price is US dollar 0.5 per dose.

CONCLUSION

In Moscow, the incidence of Hib meningitis is low and the costs of hospitalization and subsequent medical treatment are relatively inexpensive. Given these factors, Hib vaccine at US dollar 5 per dose would not be a cost-effective option in Moscow at the present time.

Are economic evaluations of vaccines useful to decision-makers? Case study of Haemophilus influenzae type b vaccines

BACKGROUND

In concert with efforts to increase global provision, economic evaluations of newer and relatively costly vaccines have proliferated in the medical literature. The extent to which existing vaccine evaluations are useful to decision makers is not clear. We conducted a systematic review of published economic evaluations of conjugate Haemophilus influenzae type b (Hib) vaccine, anticipating that their usefulness to past and present decision makers would be limited by the quality of the analyses and by the extent to which the results were transferable to other settings.

METHODS

We systematically identified economic evaluations of conjugate Hib vaccine. We appraised their quality according to a customized checklist and assessed the extent of and reasons for variability of the results.

RESULTS

Quality assessment of the available economic evaluations disclosed a number of shortcomings, including the failure across all models to derive systematic estimates of vaccine efficacy as well as a lack of transparency in the costing of Hib disease treatment. Wide variations in results appeared to be caused primarily by epidemiologic and health system differences between settings and secondarily to methodologic differences between models. The generalizability of model results appeared low.

CONCLUSIONS

There is scope for improving the overall quality of economic evaluations of Hib vaccination. Relevance to decision makers may also be increased by addressing local budget constraints and vaccine price. There is a need to better understand the decision process, particularly at the national level, to ensure the role of future economic evaluations as important decision tools in the implementation of new vaccines.

[What is an efficient health technology in Spain?]

INTRODUCTION

Despite the growing recognition of the potential applications of cost-effectiveness assessments, a criterion to establish what is an efficient health technology does not exist in Spain. The objective of this work is to describe the limits and the criteria used in Spain to recommend the adoption of health interventions.

METHOD

A review of the economic evaluations of health technologies published in Spain from 1990 to 2001 was conducted. Complete economic assessments in which the cost-effectiveness ratio was expressed as cost per life-year gained (LYG), cost per quality-adjusted-life-year (QALY) or cost per saved live were selected. Those interventions in which the authors established recommendations (adoption or rejection) and the criteria used were analyzed.

RESULTS

Twenty (20%) of the 100 complete economic evaluations fulfilled the selection criteria. In16 studies, the results were expressed as cost per LYG, in 6 studies as cost per QALY and in 1 as cost per saved live. A total of 82 health interventions were assessed and some kind of recommendation was established in 44 of them. All technologies with a cost-effectiveness ratio lower than 30,000 euros (5 million pesetas) per LYG were recommended for adoption by the authors. Up to that limit there was no a clear tendency.

CONCLUSIONS

Although the results must be interpreted with much precaution, given the limitations of the study, the limits of cost-effectiveness presented in this work could be a first reference to which would be an efficient health intervention in Spain.

Twenty years of health care economic analysis in Spain: are we doing well?

The rising demand for health care, together with the scarce available resources, has increased the use of economic analysis as a support tool for policy making. The objective of this study was to make a description of economic evaluation studies carried out in Spain and published during the last 20 years, and to assess their quality. A systematic bibliographic search was made in the main biomedical databases. Full economic evaluation studies made in Spain comparing two or more health care alternatives were included. Statistical analyses included a descriptive analysis, the assessment of the association between pairs of variables, and a homogeneity analysis. A total of 87 studies were included in the review. According to the methodology, the technique most frequently used was cost-effectiveness analysis. In most cases, some weaknesses could be pointed out: absence of any objective directly linked to the decision-making process, a non-explicit perspective, no inclusion of indirect costs, or clinical and economical data not concurrently collected. A continuing challenge for health care economic analysis in Spain is to follow methodological guidelines and reporting conventions, to improve the dissemination of research, as well as to use more sophisticated economic analysis techniques, and to publish in international journals.

Cost-benefit analysis of a Haemophilus influenzae type b meningitis prevention programme in The Philippines

BACKGROUND

Haemophilus influenzae type b (Hib) meningitis is associated with high mortality and serious sequelae in children under 5 years of age. Vaccines which can prevent this infection are available.

OBJECTIVE

To evaluate the costs and benefits of a 3-dose immunisation schedule in Manila, Philippines.

PERSPECTIVE

Government and societal perspectives.

DESIGN AND PARTICIPANTS

A cost-benefit analysis based on a birth cohort of 100,000 children. The state of health of the cohort with and without a Hib immunisation programme was modelled over a 5-year period. A survey of medical records of patients with Hib in Manila provided data on the extent and cost of sequelae following infection.

INTERVENTION

A 3-dose Hib vaccination programme given at ages 2, 3 and 4 months.

RESULTS

The model predicted that vaccinating children against Hib meningitis would prevent 553 cases per year in a birth cohort of 100,000, at a cost of 56,200 Philippine pesos (PHP) [$US1,605; 1998 exchange rate] per case (base case assumptions of 90% vaccine efficacy rate, 95 per 100,000 Hib incidence rate, 85% vaccination coverage). Results from the cost-benefit analyses indicated that the saving to the government would be around PHP39 million ($US1.11 million), and the saving to society would be PHP255 million ($US7.28 million).

CONCLUSION

There would be a positive economic benefit for the Philippine government and for the Filipino society if a Hib vaccination programme was introduced in Manila.