Universal Salt Iodization (USI) is considered among the most cost-effective investments in public health. This paper describes a tool that enables countries to develop a national Benefit Cost Analysis for, which estimates the current economic burden of IDD along with potential reductions or benefits of achieving USI.
The tool uses the World Health Organization systematic review summarizing the effect of iodized salt on change in intelligence quotient (IQ), which found median improvement of 8.18 points and a review of global evidence associating IQ and earnings, a 9.6% productivity deficit to cases of IDD is derived. The tool applies this coefficient of deficit to a hypothetical nation with a population of 50 million, birth rate of 30 per thousand, median annual earnings of $1,500 and labor participation rate of 67% along with 3% discount rate to project the magnitude of current annual loss attributable to IDD expressed as a Net Present Value (NPV).
This hypothetical case suggests the NPV of national losses reaching $448 million/year. Based a review of evidence suggesting 80% effectiveness of iodization in preventing IDD; coverage of 90% of the population with iodized salt; and a projected cost of $0.10 per person per year to sustain iodization, the tool estimates annual economic benefits of $323 million and Benefit Cost Ratio of 72.
This tool enables national projections of economic consequences and potential benefits of salt iodization. This economic perspective brings a powerful national development message that resonates with decision-makers and can assist in securing financial and political commitments.