Analytical approach:
A decision-analytic model, in the form of a decision tree, was developed to evaluate the costs and benefits of the introduction of Hib vaccination, in a hypothetical cohort of Thai children born in 2006. The disease outcomes were modelled over five years, and the long-term costs and benefits of these outcomes were modelled to the age of 60 years. The authors did not explicitly state the perspective.
Effectiveness data:
The evidence came from published national and international sources, including a meta-analysis, observational studies, and national surveys. The key clinical parameters were the Hib incidence and mortality, vaccination coverage, and vaccine wastage.
Monetary benefit and utility valuations:
The intangible benefits of vaccination were from a published survey, which obtained values using willingness-to-pay (WTP) methods.
Measure of benefit:
The primary measures of benefit were the cases of Hib and severe disability averted and Hib deaths avoided. The net present value was calculated as the overall measure of benefit.
Cost data:
The cost of the vaccination programme, the direct and indirect burden of disease, tax exemption due to disability, and lost productivity were included. The resource use was based on a hypothetical cohort. The price data were a combination of estimates from published Thai studies, tax exemption data from Malaysia, and the Thai gross domestic product for lost productivity. The price year was 2006 and the costs were reported in US dollars ($).
Analysis of uncertainty:
One- and two-way sensitivity analyses were conducted to assess the impact of parameter uncertainty. Parameters were varied by 10%. The one-way analysis varied the vaccine cost, vaccine coverage, Hib meningitis incidence, vaccine efficacy, pneumonia and meningitis incidence, discount rate, per capita income, and the disability rate.