Economic Evaluation of Hepatitis B Vaccination in Low-Income Countries: Cost-Effectiveness Affordability Curves

In the face of uncertainties about both the health and economic consequences of a vaccine program, as well as the availability and magnitude of resources needed to fund the program, cost-effectiveness affordability curves can provide information to decision-makers about the probability that a program will be both cost-effective and affordable: these are distinct but equally relevant considerations in resource-poor settings. This paper describes the application of this method to assess a hepatitis B vaccination program in the Gambia.

The authors developed a computer-based model from the societal and payer perspectives to evaluate the cost-effectiveness of routine infant vaccination against hepatitis B in the Gambia compared with no vaccination. The primary outcome measure was cost per averted disability-adjusted life year (DALY), which was expressed in 2002 US dollars. Probabilistic uncertainty analysis was used to examine the affordability of the program from the payer's perspective.

In the Gambia, vaccinating infants against hepatitis B is highly cost-effective. Compared with offering no intervention, the vaccination program would cost US$ 28 per DALY averted from the societal perspective or US$ 47 per DALY averted from the payers perspective. The program also has the potential to be affordable, starting at a relatively low budget of US$ 160,000 per year. Combining the two dimensions of the outcome measure, the probability that vaccinating infants would be both cost-effective and affordable is 40% at an annual program budget of US$ 182,000 (the estimated total program cost from the payers perspective), given a threshold cost-effectiveness value of US$ 47 per DALY averted.