The discount rate in the economic evaluation of prevention: a thought experiment.

OBJECTIVES In the standard economic model of evaluation, constant discount rates devalue the long term health benefits of prevention strongly. This study shows that it is unlikely that this reflects societal preference. DESIGN A thought experiment in a cause elimination life table calculates savings of eliminating cardiovascular disease from the Dutch population. A cost effectiveness analysis calculates the acceptable costs of such an intervention at a threshold of 18 000 Euro per saved life year. METHODS Cause specific mortality (all cardiovascular causes of death and all other causes) and health care costs (all costs of cardiovascular disease and all other causes of costs) by age and male sex of 1994. RESULTS At a 0% discount rate, an intervention eliminating cardiovascular disease may cost 71 100 Euro. At the same threshold but at discount rates of 3% or 6%, the same intervention may cost 8100 Euro (8.8 times less) or 1100 Euro (65 times less). CONCLUSIONS The standard economic model needs more realistic duration dependent models of time preference, which reflect societal preference.