QALYS and DALYS as synthetic indicators of health

This article is a revision of the genesis and use of the health synthetic indicators QALYs and DALYs. The chronology of their appearance is shown and similarities and differences between them stated. DALYs (Disability-Adjusted Life-Years) correspond to years of life that are adjusted by a certain level of disability experienced during a particular period of time. DALYs, by studying disease burden, summarize the impact of mortality and disability related to specific disease in different communities. On the other hand, QALYs (Quality-Adjusted Life-Years) summarize health results in an indicator that combines the number of years lived with the quality of life experienced over those years. QALYs and DALYs play a crucial role as results measures in economic evaluation studies (cost-effectiveness and cost-utility analysis) measuring the impact of actions or specific interventions in the reversion of disease burden (DALYs) and/or the improvement of the quality of life and life expectancy of patients (QALYs). Their generic character allows the comparison of the impact of health interventions for different diseases.