3rd Global Meeting on Implementing New and Under-utilized Vaccines, 16-18 June 2009
Workgroup 6. Pneumococcal conjugate vaccine cost-effectiveness assessments
Background
There is an increased demand for economic analyses to assist country decision-making to introduce new vaccines. Cost effectiveness of vaccination programmes are based on mathematical modelling, which should yield a framework and help synthesize information from many sources, and also help extrapolate data beyond clinical trials.
Currently, there are several mathematical models and economic analysis models for PCV vaccination, varying from country-specific models to generic tools that support decision-making designed to be adaptable to local circumstances. Given the importance of the data generated by these tools, it is critical to evaluate them to ascertain their robustness and applicability and to discuss how policy makers can best use them to inform vaccine policy.
Main Topics of Discussion
- These evaluations and tools are an aid to decision-making, because they help to explore additional likely scenarios for the need and the optimal strategies for vaccine introduction. They provide results in terms of their cost and benefits. In addition, given the paucity of quality data they can also provide indication of the uncertainties and assumptions used in the analysis.
- The adequate use of such decision making support tools contributes to increase the transparency of the decision making process.
- Appraisals of models and cost effectiveness assessments can aid decision makers to refine the priority public health questions. They can help them to ascertain whether models are robust (in terms of model structure, parameters values and validation process) or how the model and cost effectiveness assessment results can be interpret and used to inform policy.
- Given the inherent complexity of this type of analysis, it is important to assess which input parameters and assumptions are critical drivers of the outcomes.
- Similarly, it is useful to compare the different mathematical models to learn about the different model structures, and their key assumptions, as well as to discuss the process which leads to different results.
- This type of review can also help inform surveillance needs and promote a more integrated approach to data gathering and analysis. The use of the tools, and importance of focusing efforts in collecting quality data for key parameters has implications at the country level.
- Systematic literature review of cost effectiveness studies is important - comparative descriptions of model inputs, assumptions, attributes and differences between individual studies and implications were discussed.
- A systematic literature review on cost-effectiveness of PCV showed that only two studies focus on low and middle income countries.
- It would be useful to compare decision support tools for PCV with those for other vaccines to allow for sector wide priority setting in health care.
In relation to the models and tools reviewed during this section, main discussion points include:
- None of the models evaluated described a validation process.
- Most modellers acknowledged that their model is static and may not account for dynamic transmission characteristics of Streptococcus pneumoniae infection.
- Some of the parameters deemed to greatly influence the results include vaccine cost, vaccine efficacy and disease incidence data.
Recommendations
Mathematical models and cost-effectiveness assessments should be used as tools to evaluate the impact of interventions under various likely scenarios. Their sole use as advocacy tools in support of a given choice is not adequate. In order to promote their rational use, the following recommendations were made:
- WHO should continue to critically evaluate (using set criteria) mathematical models, cost-effectiveness assessments and decision support tools such as cost-effectiveness models for PCV and other new vaccines.
- The results of such appraisals should be publicly disseminated. Dissemination efforts must include reaching out to stakeholders and decision makers at regional and country level. Efforts must include steps to inform them about the rational use of existing models, cost-effectiveness assessments and tools.
- Additional country based models and cost-effectiveness analysis of PCV are needed to better support vaccine introduction decisions at national level.
- Capacity strengthening in this area at the country level is a critical step in promoting the rational use of these evaluations and tools.
- Work on broader-level decision-making tools for the overall health sector should be encouraged.