Estimate the impact of PSI interventions in selected countries, compare and download results, and explore information about the models used to estimate impact by clicking on the intervention name.
Updated Jul 26, 2019
Zinc in combination with oral rehydration salts (ORS) has been shown to reduce the duration and severity of diarrhea. WHO and UNICEF recommend the use of this combination as a safe, effective and inexpensive diarrhea treatment for children in the developing world1. PSI promotes diarrhea treatment kits (DTKs) with a pre-packaged combination of two ORS sachets and ten dispersible zinc tablets.
Unit of intervention1 treatment kit
Contents2 ORS sachets and 7-10 dispersible zinc tabletsFormula for 1 ORS sachet
Formula for 1 tablet of zinc20 milligrams of elemental zinc per tablet
Treatment course for an episode of diarrheaContents of one treatment kit
Target populationChildren under five with diarrhea
For information about how PSI is increasing access to diarrhea treatment kits to improve health and save lives, visit our website at:
PSI’s DTK impact model is based on the Lives Saved Tool (LiST). LiST is used to estimate the number of deaths averted with complete coverage of DTKs for treatment of diarrhea among children under age five in a country. This number of deaths averted at the population level is translated to deaths averted per DTK, using parameters such as baseline coverage of ORS and zinc, DTKs needed per episode of diarrhea, and diarrhea incidence rates. Once we have deaths averted per DTK, we apply data from the 2010 Global Burden of Disease study to estimate the corresponding number of DALYs averted.Model Outputs (impact metrics)
Estimates of DALYs averted, deaths averted, CYPs provided, and unintended pregnancies averted represent the projected health impact of the intervention. It is
projected because it has not been directly measured.
In 2015, an estimated 6 deaths and 570 DALYs would be averted if 10,000 diarrhea treatment kits were distributed in Myanmar.
For more details about how PSI models the impact of diarrhea treatment kits, see below.
Step 1: Running a projection in the Lives Saved Tool (LiST)LiST is a multi-cause mortality model developed by Johns Hopkins Bloomberg School of Public Health that estimates the number of deaths averted (or lives saved) through the scale up of maternal and child health interventions.
PSI begins by running a projection in LiST for a selected country. In this projection, coverage of DTKs is increased from the current, country-specific baseline to 100% among children under five. LiST then projects the number of deaths averted by this increased level of coverage.
Step 1 Output:
Number of deaths averted (or lives saved) if coverage of DTKs is increased to 100% among the children under age five years in a given country
Step 2: Estimating deaths averted per diarrheat treatment kit (deaths averted coefficient)PSI uses the step 1 output (deaths averted at 100% coverage of DTKs) to estimate the number of deaths averted by a single DTK. To do this, we divide the number of deaths averted at 100% coverage by the number of DTKs needed to reach 100% coverage.
PSI estimates the number of DTKs needed to reach 100% coverage using a number of parameters, including as baseline coverage of ORS and zinc, DTKs needed per episode of diarrhea, and diarrhea incidence rates. Each case of diarrhea is assumed to require one DTK. We also account for wastage of DTKs in the supply chain, assumed to be 10%.
Step 2 Output:
Deaths averted coefficient
Step 3: Estimating DALYs averted per diarrhea treatment kit (DALYs averted coefficient)A DALY (or disability adjusted life year) includes two components: years of life lost due to premature death (YLL) and years lived with disability (YLD). DALYs averted are in turn comprised of YLLs averted and YLDs averted or, put simply: death and disability that is prevented by PSI interventions.
To estimate YLLs averted per unit of DTK, PSI first estimates the number of years of life lost per diarrhea death among children under five in a selected country. This is equal to the life expectancy at the average age of death from diarrhea. Age specific life expectancy is taken from the 2010 Global Burden of Disease study (GBD 2010). The number of years of life lost per diarrhea death is then multiplied by the number of deaths averted per DTK (deaths averted coefficient), calculated in step 2 above for a selected country. This gives us the YLLs averted per unit of DTK.
To estimate YLDs averted per unit of DTK, we use a YLD/YLL ratio, based on GBD 2010. This ratio represents the relative number of years lived with disability for every year lost due to death from diarrhea in a selected country. We apply this ratio to the number of YLLs averted per DTK to estimate the number of YLDs averted per DTK. Because DTKs treat diarrhea, rather than prevent it, we assume that individuals will still suffer some disability before and during treatment. Therefore, we only include half of the total YLD averted in our estimate. This is a standard assumption in all of our treatment models.
Finally, YLLs averted and YLDs averted are added together to estimate the number of DALYs averted per DTK.
Step 3 Output:
DALYs averted coefficient