Read the briefing paper on health impact.

Visit the PSI Health Impact Calculator.


Metric: Disability-Adjusted Life Years (DALYs) averted

Why measure health impact?

Measuring health impact makes it possible for a program to know if it has achieved what it set out to do: improve population health.

Outputs like clients served and services used are often measured and tracked by programs. However, clients served does not tell the broader story of how many clients successfully completed services. Services used does not take into account the varying degrees of health benefits provided by different types of health services and commodities. Health impact measurement is a more robust way of estimating the public health value of a program. Measuring health impact is also an important precursor for understanding the cost-effectiveness of a program.

Why measure health impact using a standardized metric?

Consistent use of the same metric permits comparison across years, and across programs. This type of analysis can lead to better programmatic decision making.

How can health impact be measured?

Most programs maintain records of how many health services (including referrals and diagnostic tests) and commodities are provided in a given year. These statistics can be run through a mathematical model, which attaches a country-specific coefficient (or estimate of health impact per unit of intervention) to each item. Each coefficient is based on assumptions of the health benefits provided by a particular health service or commodity within a given country. Results are expressed in the form of Disability- Adjusted Life Years (DALYs) averted. This is a summary estimate of health benefits resulting from treating an illness or avoiding unplanned pregnancies or a disease. One DALY averted means that the services provided by a program resulted in a year of healthy life saved.

DALYs averted takes into account the wide range of services that are now offered by health service programs, unlike Couple Years of Protection (CYPs), which measure the impact of family planning services and commodities only.

Systematically collected health impact data has valuable uses

  • Measure performance across years, programs, and health service areas
  • Make evidence-informed program decisions
  • Measure cost-effectiveness
  • Report to donors and policy-makers
  • More broadly, these data are useful for setting global benchmarks

PSI Health Impact Calculator

PSI has developed a health impact calculator to estimate and compare the potential impact of health interventions. Although the tool focuses on PSI programs and interventions, it can be applied to programs around the world. You can calculate health impact by country, as well as learn about how these values are calculated and how to communicate this information to your constituency.

To learn more about how to use the calculator, please review:

To use the calculator, visit