PSI evaluates the health impact of its interventions using a variety of metrics and research tools and has an aggressive goal of doubling its health impact between 2007 and 2011. PSI calculates that we will be averting more than 20 million Disability Adjusted Life Years (DALYs) per year by 2011, by preventing 300,000 HIV infections, 243,000 deaths from malaria, 19,000 deaths from diarrhea and 6.8 million unintended pregnancies annually.

What is a DALY?

PSI adopted the DALY in 2006 as our key performance metric to estimate the health impact of its products and behavior change interventions, and to inform programmatic decision-making. One DALY is equal to one year of life lost to illness or death. When PSI averts one DALY, it means that PSI has prevented the loss of one year of productive, healthy life – a year of life that, without PSI’s intervention, would have been lost to illness or death. In 2009, PSI averted 15.1 million DALYs.

PSI calculates DALYs averted by its programs using a DALY calculator, which is based on models that have been developed with input from external partners. The DALY calculator is based on the latest local epidemiology and demography; the best evidence available on protective effectiveness and lifespan of each intervention program; and program-specific information such as the rate of waste and misuse of products, and adherence and compliance by users. The development of any model is an evolutionary process, and PSI plans to continually refine and improve the calculator.

Related links:

• DALY FAQ
• Health Impact Reports
• Measuring the Impact of Behavior Change Communications
• Burden of Disease Estimates