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Free DFS - Intervention to fight anemia and improve well-being in a very low income setting
Last registered on May 15, 2013


Trial Information
General Information
Free DFS - Intervention to fight anemia and improve well-being in a very low income setting
Initial registration date
Not yet registered
Last updated
May 15, 2013 10:14 AM EDT
Primary Investigator
CESS Nuffield - FLAME University
Other Primary Investigator(s)
PI Affiliation
PI Affiliation
Additional Trial Information
On going
Start date
End date
Secondary IDs
Iron deficiency anemia (IDA) has been linked to low productivity in adults, slowing of cognitive and physical growth among children and, in the elderly, increased risk of cognitive impairment and physical disability, as well as decreased muscle strength. While iron deficiency anemia has been recognized to be a serious public health problem in developing countries for several years, something that both limits the working population and increases risks for cognitive impairment and health shocks in the elderly, not much progress has yet been made against it. Distributing iron supplements appears to be an impractical policy in resource-poor settings where the public health systems do not have the capacity to maintain a large-scale distribution system. Iron supplementation of foods is therefore an attractive alternative: it requires no additional effort on the part of the consumer, and can be done relatively cheaply in centralized locations.

This study measures the impact of giving free Double (Iron and Iodine) Fortified Salt to randomly assigned households in 62 villages, compared to households who were randomly assigned to no free salt. The households which we give DFS will still choose whether to use free DFS or not, which will constrain potential health benefits. We expect to observe increases in haemoglobin, particularly among individuals anemic at baseline if households respond to the offer of free salt by using it to cook human food.
External Link(s)
Registration Citation
Banerjee, Abhijit, Sharon Barnhardt and Esther Duflo. 2013. "Free DFS - Intervention to fight anemia and improve well-being in a very low income setting." AEA RCT Registry. May 15. https://doi.org/10.1257/rct.10-1.0.
Sponsors & Partners

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Experimental Details
We deliver free Double Fortified Salt manufactured in India by Tata Chemicals Ltd. to homes of subjects at the rate of 0.8 kg per month per treated household for approximately 7 - 11 months.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
Hemoglobin level, physical health, cognition (memory), school/work attendance and time use.
Primary Outcomes (explanation)
Hemoglobin level measured by hemocue, anemia, BMI, Mid-Upper Arm Circumference, Number of Activities of Daily Living that can be completed, Self-reported health, Queens College Step Test, Time to walk 4 meters, Time to sit and stand up 5 times in a row, Depression index based on the CES-D from self-reports on mental states.

The Lucknow Development Screen for infant development, Memory batteries for children (digit spans from PGI Memory Scales and block tapping test from the NIMHANS child neurpsoychology tests), Memory for adults (four subtests of the PGI Memory Scale), Hindi Mental State Exam for adults over 50.

School attendance, work attendance, value of consumption, and time use including hours of work.
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
We randomly selected 62 villages participating in another trial where Double Fortified Salt is being made available for sale in stores and where a baseline survey had been completed with all members of 15 households per village. We randomly assigned 7 households per village to receive free DFS and the other 8 households to not receive free DFS.
Experimental Design Details
Randomization Method
Computer generated randomization done in office outside study district.
Randomization Unit
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
930 households
Sample size: planned number of observations
6045 individuals
Sample size (or number of clusters) by treatment arms
2821 individuals free DFS, 3224 individuals no free DFS
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials

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IRB Name
IFMR (Chennai)
IRB Approval Date
IRB Approval Number
IRB00007107; FWA00014616; IORG0005894
IRB Name
IRB Approval Date
IRB Approval Number
Post Trial Information
Study Withdrawal
Is the intervention completed?
Is data collection complete?
Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)