[Quality adjusted life years in assessment of preventive measures. Should blood donors be tested for HTLV-I/II infections?].

In planning preventive health measures, quality adjusted life-years (QALYs) are useful as a measure of benefit. As an example, the question of whether blood donors should be routinely tested for antibodies to the Human T-lymphotropic viruses I and II (HTLV I/II) is analysed. A mathematical model was set up to describe the consequences, in terms of lost life-years and years with disease due to transfusion-mediated infection (if testing is not performed) or years with reduced quality of life (in the case of testing). These future outcomes were discounted and converted to QALYs. The cost per QALY is about NOK 2.33 million when the prevalence is 1 per 50,000 blood donors, and is reduced to 190,000 per QALY when the prevalence is 10 per 50,000. Using QALYs in evaluation of preventive medicine can be complicated, and calls for cooperation between epidemiologists and health economists.