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Field
Trial Status
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Before
completed
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After
on_going
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Field
Trial Start Date
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Before
March 15, 2019
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After
May 05, 2022
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Field
Trial End Date
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Before
December 30, 2020
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After
December 31, 2023
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Field
Last Published
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Before
December 14, 2021 05:50 AM
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After
March 31, 2023 07:12 AM
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Field
Intervention (Public)
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Before
Our interventions comprise the following broad components:
Monitoring: Biweekly health worker (hereafter, HW) visits to - a) collect data on diarrhea incidence over the last two weeks, b) test chlorine in the water, and c) offer free chlorine tablets (2-week’s supply) along with expert advice on use. These mimic standard public health campaigns around chlorine distribution.
Info-tool: HW helps the caregiver record diarrheal incidence (unique episodes across children) and total diarrhea days (the sum of all diarrhea days across episodes and children) and creates a bar graph to visually represent the total diarrhea days experienced by the children in the household in the last two weeks. At the end of each month (i.e. during the second biweekly visit in a month), the diarrhea days from that month are added up and colored into a month-level bar graph;
Social Norm: HW shares information on the monthly diarrhea days expected in households that do not use chlorine (to be estimated using data directly from the experiment); and
Habit formation with financial incentive: Caregivers are offered rewards (tokens redeemable for child or household goods) if water tested positive for chlorine; size of incentive to be calibrated to match the short-run take up of tablets in T1 (see experimental design below).
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After
We propose a randomized controlled trial (RCT) across 1,800 households. We first describe the various components of our interventions, and then outline the treatment arms explicitly.
Monitoring: Biweekly health worker (HW) visits to: a) collect data on diarrhea incidence over the last 2 weeks; b) test chlorine in the water once per month; and c) offer free chlorine tablets (2-week’s supply) and expert advice on use. This mimics standard public health campaigns on chlorine distribution.
Info-tool: HW helps the caregiver record diarrheal incidence (unique episodes across children) and total diarrhea days (the sum of all diarrhea days across episodes and children), and creates a bar graph to visually represent the total diarrhea days experienced by the children in the last 2 weeks. At the end of each month (during the second biweekly visit in a month), the diarrhea days from that month are added up and colored into a month-level bar graph. This is a simple, visual paper-and-pencil tool, and AM (2017) and our recent pilots have demonstrated that low-literacy-numeracy caregivers are comfortable using it.
Benchmarks: HW shares information on the diarrhea days expected in households (over the last two weeks) that do not use chlorine (estimated using data from the experiment; more on this below); and
Habit formation with financial incentive: Caregivers are offered small daily rewards (tokens redeemable for child/household goods) if the caregiver can show empty chlorine tablet wrappers as proof of usage. Each daily reward for proper chlorine use is equal to approximately 5 US cents (with ‘proper use’ calibrated to household’s pre-intervention water consumption).
Our four experimental arms are as follows:
Comparison (C): Monitoring minus the offer of free chlorine tablets and chlorine-testing
Treatment 1 (T1): Monitoring
Treatment 2 (T2): Monitoring + Info-tool + Benchmark
Treatment 3 (T3): Monitoring + Habit formation with financial incentive
To determine the benchmark in T2, we will use the diarrhea results of C from the previous two weeks. HW will share this information during the bi-weekly visits starting from the second visit (using data from the first bi-weekly visits to C from the previous two weeks).
Comparisons of arms and corresponding research questions are:
T1 vs T2: What are the short and long-run effects of facilitating learning about health returns on tablet take-up and usage?
T2 vs T3: Which mechanism is more effective in generating both contemporaneous and sustained change in behavior - active learning (via Info-tool and benchmark) or habit formation (with temporary incentives)?
C vs T1: How do the effects above compare to the standard public health effort of free distribution alone?
The interventions will span months 1-6 of the experiment (Phase 1), during which HWs visit all households once every two weeks for data collection and intervention execution. Note that, for the three treatment arms, tablet distribution and testing of water (and hence incentives for T3) starts in the third month as we reserve the first two months to help the caregivers develop some pre-tablet-access record of diarrhea incidence in their households. For months 7-16 (Phase 2), HWs will visit all households once each month to observe changes in long-term behavior. In month 16, HWs will offer a final 3-month’s supply to all households (except C). An endline survey will be administered 1 month after this visit.
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Field
Intervention Start Date
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Before
April 01, 2019
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After
June 10, 2022
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Field
Intervention End Date
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Before
March 31, 2020
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After
November 30, 2022
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Field
Experimental Design (Public)
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Before
Our interventions or experimental arms comprise the following broad components:
Monitoring: Biweekly health worker (hereafter, HW) visits to - a) collect data on diarrhea incidence over the last two weeks, b) test chlorine in the water, and c) offer free chlorine tablets (2-week’s supply) along with expert advice on use. These mimic standard public health campaigns around chlorine distribution.
Info-tool: HW helps the caregiver record diarrheal incidence (unique episodes across children) and total diarrhea days (the sum of all diarrhea days across episodes and children) and creates a bar graph to visually represent the total diarrhea days experienced by the children in the household in the last two weeks. At the end of each month (i.e. during the second biweekly visit in a month), the diarrhea days from that month are added up and colored into a month-level bar graph;
Social Norm: HW shares information on the monthly diarrhea days expected in households that do not use chlorine (to be estimated using data directly from the experiment); and
Habit formation with financial incentive: Caregivers are offered rewards (tokens redeemable for child or household goods) if water tested positive for chlorine; size of incentive to be calibrated to match the short-run take up of tablets in T1.
Using combinations of the above, we propose the following four experimental arms:
Comparison (C): Monitoring
Treatment 1 (T1): Monitoring + Info-tool
Treatment 2 (T2): Monitoring + Info-tool + Social Norm
Treatment 3 (T3): Monitoring + Habit formation with financial incentive
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After
We propose a randomized controlled trial (RCT) across 1,800 households. We first describe the various components of our interventions, and then outline the treatment arms explicitly.
Monitoring: Biweekly health worker (HW) visits to: a) collect data on diarrhea incidence over the last 2 weeks; b) test chlorine in the water once per month; and c) offer free chlorine tablets (2-week’s supply) and expert advice on use. This mimics standard public health campaigns on chlorine distribution.
Info-tool: HW helps the caregiver record diarrheal incidence (unique episodes across children) and total diarrhea days (the sum of all diarrhea days across episodes and children), and creates a bar graph to visually represent the total diarrhea days experienced by the children in the last 2 weeks. At the end of each month (during the second biweekly visit in a month), the diarrhea days from that month are added up and colored into a month-level bar graph. This is a simple, visual paper-and-pencil tool, and AM (2017) and our recent pilots have demonstrated that low-literacy-numeracy caregivers are comfortable using it.
Benchmarks: HW shares information on the diarrhea days expected in households (over the last two weeks) that do not use chlorine (estimated using data from the experiment; more on this below); and
Habit formation with financial incentive: Caregivers are offered small daily rewards (tokens redeemable for child/household goods) if the caregiver can show empty chlorine tablet wrappers as proof of usage. Each daily reward for proper chlorine use is equal to approximately 5 US cents (with ‘proper use’ calibrated to household’s pre-intervention water consumption).
Our four experimental arms are as follows:
Comparison (C): Monitoring minus the offer of free chlorine tablets and chlorine-testing
Treatment 1 (T1): Monitoring
Treatment 2 (T2): Monitoring + Info-tool + Benchmark
Treatment 3 (T3): Monitoring + Habit formation with financial incentive
To determine the benchmark in T2, we will use the diarrhea results of C from the previous two weeks. HW will share this information during the bi-weekly visits starting from the second visit (using data from the first bi-weekly visits to C from the previous two weeks).
Comparisons of arms and corresponding research questions are:
T1 vs T2: What are the short and long-run effects of facilitating learning about health returns on tablet take-up and usage?
T2 vs T3: Which mechanism is more effective in generating both contemporaneous and sustained change in behavior - active learning (via Info-tool and benchmark) or habit formation (with temporary incentives)?
C vs T1: How do the effects above compare to the standard public health effort of free distribution alone?
The interventions will span months 1-6 of the experiment (Phase 1), during which HWs visit all households once every two weeks for data collection and intervention execution. Note that, for the three treatment arms, tablet distribution and testing of water (and hence incentives for T3) starts in the third month as we reserve the first two months to help the caregivers develop some pre-tablet-access record of diarrhea incidence in their households. For months 7-16 (Phase 2), HWs will visit all households once each month to observe changes in long-term behavior. In month 16, HWs will offer a final 3-month’s supply to all households (except C). An endline survey will be administered 1 month after this visit.
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Randomization Unit
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Before
Household (with at least one under-five child)
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After
Household (with at least one child between the ages of 6 months and 5 years old at baseline)
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Field
Planned Number of Clusters
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Before
1,400 Households
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After
1,800 Households
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Field
Planned Number of Observations
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Before
1,400 Households
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After
1,800 Households
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Field
Sample size (or number of clusters) by treatment arms
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Before
350 Households
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After
450 Households
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Field
Power calculation: Minimum Detectable Effect Size for Main Outcomes
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Before
1. Presence of residual chlorine in household drinking water (proportion; MDE: 11 pp)
2. Acceptance of offered chlorine tablets (proportion; MDE: 11 pp)
3. Number of days a child under five had diarrhea (days; MDE: 0.176)
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After
Our census has identified 1,800 eligible households (those with at least 1 under-5 children), who will be individually randomized into the 4 arms, with each arm comprising 450 households. Given 10% attrition, 5% significance level and 80% power, for any pair-wise comparison of arms, this implies a minimum detectable effect size of 9.3 pp (in residual chlorine presence in drinking water; baseline mean, 29%, from our piloting data) and 0.2 SD (in diarrhea days; 76% of baseline mean in Hussam, et al, (2021)). For the anthropometric outcomes such as height-for-age or weight-for-height z-scores, note that many households (45% in our pilot sample) have two or more under-five children. Taking this into account, we estimate a minimum detectable effect size of 0.158 SD with the following underlying parameters: 720 under-five children per arm (using the pilot study estimate of the mean number of children per household), intra-household correlation in height-for-age z-score of 0.05 (from a recent study by Akram, Khan et al. from another informal settlement in the same city), as well as 10% attrition, 5% significance level, and 80% power.
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Field
Keyword(s)
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Before
Health
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After
Behavior, Health
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Field
Did you obtain IRB approval for this study?
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Before
No
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After
Yes
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