Willingness-to-pay for a population program aimed at reducing dietary salt in Denmark.

Abstract

High intake of salt increases blood pressure and the risk of cardiovascular disease. Population programs aimed at reducing dietary salt may be cost-effective, but little is known about people's valuation of such programs. A random sample (n = 924) of Danish people aged 20-74 was interviewed in-person in year 2000. They were asked how much they would be willing to contribute in additional tax for a population program that would half the intake of salt. The respondents were randomized to presentation of effectiveness format (number-needed-to-treat (NNT), relative risk reduction (RRR), avoided cases of heart attack or increase in longevity). In total, 57% were unwilling to contribute to the program (63%, 51%, 51% and 63% in the NNT-, RRR-, case- and longevity-groups, respectively). The mean willingness-to-pay among the remaining 43% was $30 per person per month. While in Denmark, the annual net program cost would be $148 millions in the most unfavorable scenario, the aggregate willingness-to-pay was $468 millions. A public health program may be worthwhile even though only a minority of the population is willing to contribute towards it. People's valuation is moderately sensitive to format of the program information.