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ValueSourceNotes
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Inputs
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Cost per child covered per vitamin A supplementation round$1.35
Main GiveWell cost-effectiveness analysis
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Vitamin A supplemneation rounds per year2
Main GiveWell cost-effectiveness analysis
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Cohort100,000Arbitrary
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Night blindness disability weight0.003Salomon et al. 2015
Using the disability weight for mild visual impairment
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Night blindness prevalence in Guinea, Burkina Faso, and Mali1.3%
https://ourworldindata.org/grapher/prevalence-of-night-blindness-in-pre-school-children
Our World in Data, citing WHO estimate from 1995-2005. Using a simple average for simplicity.
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Relative risk of night blindness following VAS0.32
Imdad et al. 2017 (VAS Cochrane review)
Based on two RCTs with 22,972 participants.
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Years of night blindness averted by preschool-aged VAS5Andrew's guess
My general understanding is that preschool-aged children are more likely to have VAD symptoms than school-aged children. In absence of VAS, my guess is that children would at some point have a vitamin A status high enough to alleviate night blindness, but I'm not very certain about this.
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Calculations
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Cost to cover cohort for one year$270,000Calculation
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DALYs averted14Calculation
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Cost per DALY averted$19,853Calculation
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Results
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Units of value per $10,000 donated, GiveDirectly10
https://docs.google.com/spreadsheets/d/1IhtZJcWWUQRndEHFHgty5OLdLL4FkNbFMTsKcwGz03g/edit?usp=sharing
Using Andrew's value for simplicity. One unit of value for me roughly equals one DALY averted.
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Units of value per $10,000 donated, night blindness prevention benefits0.5Calculation
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Night blindness prevention benefits for VAS are X times as cost-effective as GiveDirectly
0.05Calculation
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