COSTS OF PREDICTING IDDM

Programmes aiming at prediction and prevention of insulin-dependent di abetes mellitus (IDDM), a multifactorial autoimmune disease, have been launched or are in the planning phase in several countries. We hypoth esized that the costs of finding the correct target subjects for preve ntive interventions are likely to vary markedly according to the predi ction strategy chosen. Average direct costs accruing in the Finnish ID DM Prediction and Prevention Project (DIPP) were analysed from the hea lth care provider's viewpoint. The genetically targeted strategy inclu ded costs of assessing genetic IDDM susceptibility followed by measure ment of marker(s) of islet autoimmunity in the susceptibility restrict ed population at 3 to 6-month intervals. In the pure immunological str ategy markers of autoimmunity were repeatedly analysed in the entire p opulation. The data were finally exposed to sensitivity analysis. The genetically targeted prediction strategy is cost-saving in the first y ear if autoimmune markers are analysed as frequently as under the DIPP project, and in all circumstances later. The 10-year direct costs per child are US$ 245 (present value $ 217, 5% discount rate) if the gene tically targeted approach is used and $ 733 (present value $ 619) if t he pure immunological strategy is chosen. In sensitivity analysis the 10-year costs (present value) per child of the genetically targeted st rategy and of the pure immunological strategy varied from $ 152 to $ 2 41 and from $ 430 to $ 788, respectively. The genetically targeted IDD M prediction strategy is remarkably cost-saving as compared with the p ure immunological strategy mainly because fewer subjects will need ret esting during the follow-up.