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Improving Diets in Schools in Vietnam: Testing Innovative Methods of Influencing Demand
Last registered on June 03, 2019

Pre-Trial

Trial Information
General Information
Title
Improving Diets in Schools in Vietnam: Testing Innovative Methods of Influencing Demand
RCT ID
AEARCTR-0003779
Initial registration date
January 08, 2019
Last updated
June 03, 2019 11:21 AM EDT
Location(s)

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Primary Investigator
Affiliation
International Food Policy Research Institute
Other Primary Investigator(s)
PI Affiliation
Wageningen University and Research
PI Affiliation
National Institute of Nutrition, Vietnam
PI Affiliation
Wageningen University and Research
Additional Trial Information
Status
In development
Start date
2019-02-18
End date
2019-12-31
Secondary IDs
Abstract
Schools are an attractive leverage point for improving diets, thanks to their continuous and intensive contact with children and youngsters whose eating habits can be shaped and the high potential to reach adults through children. In Vietnam, several initiatives to promote healthier diets have taken place, but attempts to increase children’s motivation to eat healthier have been sparse and not been assessed to be successful. In Dong Anh, consumption of fruits and vegetables is suboptimal and overweight and obesity among children a worrying health consequence. This study will assess how school-based nutrition education will increase children’s consumption of healthy foods, and how this helps to increase the parents’ knowledge of healthy food, obesity, and healthy diets. We will implement two interventions: First, this research will provide children with the opportunity to learn about food and nutrition in the school meal setting, contrary to the usually detached nutrition lessons. The design of nutrition lessons incorporates insights from behavioral economic literature. Children will be encouraged to share what they have learned during the nutrition education sessions with their family members. Second, healthy snacks will be provided during the break of the treated children. The activity is designed in collaboration with the National Institute of Nutrition.

The research employs a clustered randomized control trial. The study population are of 3rd, 4th and 5th graders from all primary schools in the Dong Anh District, out of which 12 schools will be sampled to participate in the research. The unit of intervention planned will be 3th, 4th and 5th grade classes within the schools. In each school (as a block), all the classes in one or two of the three grades (randomly selected from the 3 grades) will be in the treatment group, while all the classes in the remaining grades will be in the control group.
External Link(s)
Registration Citation
Citation
de Brauw, Alan et al. 2019. "Improving Diets in Schools in Vietnam: Testing Innovative Methods of Influencing Demand." AEA RCT Registry. June 03. https://doi.org/10.1257/rct.3779-3.0.
Former Citation
de Brauw, Alan et al. 2019. "Improving Diets in Schools in Vietnam: Testing Innovative Methods of Influencing Demand." AEA RCT Registry. June 03. https://www.socialscienceregistry.org/trials/3779/history/47416.
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Experimental Details
Interventions
Intervention(s)
Treatment 1: The treated children will be given lunch time presentations (nutrition information communication) and encouraged to share their knowledge with their parents (child-parent communication about healthier diets).

Due to the limited time and facility available at schools, we will keep the nutrition education and communication activities for children short and relevant. The messages focus on the balanced diets, the recommended daily consumption of fruits and vegetables, the benefits of fruits and vegetables, and how to incorporate more fruits and vegetables into their meals. The teachers will be trained by NIN specialists to provide this message to children in a 5-minute show-and-tell talk right before the lunch time. Complementing the presentation will be leaflets/posters with the same contents. The materials for this activity are developed by NIN.

Children will be encouraged (with age-appropriate in-kind rewards such as stickers bearing fruits and vegetables cartoons) to share what they have learned during the nutrition education sessions with their family members. The children will be given tips to communicate with their parents, as well as provided with supplementary communication material (leaflets bearing the same contents as the lessons for children) to give their parents. The parents are requested to sign a form confirming their receipt of the leaflets, as well as commitment to help children eat more fruits and vegetables.

The parents will also be provided with instructions on how to provide recommendations for the school meals to food contractors and schools. They can send text messages to a dedicated line, or return a filled survey to the schools voicing their opinion of the school food.

These treatment activities last for 5 weeks. Lesson plans and materials for each week are designed by NIN and supplied to the teachers on the training day.


Treatment 2: In addition to the Treatment 1, the treated will also be provided with healthy snacks during the afternoon breaks.

In Dong Anh, no snack is provided during the breaks, which prompted children to either bring their own snacks (e.g. sweetened milk or cakes, hardly fruits or nuts) or buy processed snacks outside schools. We will recruit a contractor for supplying seasonal fruits as snacks to the schools, ensuring the selected company meets legal, safety and any school-based requirements to provide food for children at school. The fruit will be provided for children during the morning break, so that it does not clash with the on-going school milk program (where children drink bottled milk during the afternoon break). The snacks will serve as (i) outcome measurement: if the information session motivates the children to eat more FAV, and (ii) a default healthier option, which can potentially replace their less healthy snacks.

This snack provision will also take place in 5 weeks on a sub-set of children who were given nutrition lessons.

Control: No intervention on the control group. Children and parents in the control group are given the same instructions as those in the treatment group to complete the food diaries.
Intervention Start Date
2019-03-11
Intervention End Date
2019-05-31
Primary Outcomes
Primary Outcomes (end points)
The experiment has two groups of outcome variables: one for the children and one for their parents.
Outcome variables for children:
- Knowledge about vegetables and fruits
- Attitude towards vegetable and fruit consumption
- Consumption of fruits and vegetables at school
- Consumption of fruits and vegetables at home
Outcome variables for parents:
- Knowledge about vegetables and fruits
- Attitude towards vegetables and fruit consumption
- Consumption of fruits and vegetables
Primary Outcomes (explanation)
The study will involve 3 data collection rounds: baseline, endline 1 (right after the intervention ends) and endline 2 (six months after endline 1). Baseline data will be used to validate the assumptions, adapt the theories, re-estimate the power, and adjust the pre-analysis plans accordingly. Besides, balance tests will be performed on baseline data to check if randomization has resulted in groups similar in relevant covariates. We will use standard data analysis techniques used in randomization studies to measure the treatment effects (Khandker, B. Koolwal, & Samad, 2009).
Outcome variables for children:
A KAP (knowledge, attitude and practice) questionnaires will be used to measure the knowledge of and attitude towards vegetable and fruit consumption. A FAV consumption frequency question will be included under “Practice”. The questionnaire will be carried out in a face-to-face interview with children.
To measure the consumption of fruits and vegetables at school, research assistants (RA) will observe the children during lunch time/afternoon snacks to fill in the school food diaries. The food diary will not only cover fruits and vegetables, but also other foods, to put fruit and vegetable consumption in the overall context of a diet.
Lunch time: In Dong Anh, all the lunches in schools are provided in food trays with standardized foods (portioned by the school food provider staff). The RAs will hand in the food trays (with stickers to identify the sampled children). After children finish eating, they will collect the identified trays, measure the leftover (or extra food – the RA can see if he/she asks for extra food from the teacher/enumerator; and/or estimate the amount of food she/he was given by another student) and fill in the school food diaries for each children.

Morning break: The RAs will observe if the children pick up the provided food or take the food home and fill in the school food diary.

School food diaries will be done in 2 days of the school week (e.g. Tuesday and Thursday; Wednesday and Friday, Monday and Wednesday).

To measure the consumption of fruits and vegetables at home, children will be instructed by RAs to fill in the home food diary at home themselves (with the parents’ help if necessary). The home food diaries will also be done in 3 days, so that what the children eat during the weekend is also recorded.
Outcome variables for parents:
A KAP survey for parents will be implemented to measure the knowledge and attitude towards fruits and vegetables consumption. The parents will be instructed by RAs to fill in the food diary themselves. The food diaries will also be done in 2 days as per the school food diaries.
The following variables/indicators will be used to assess the knowledge level on FAV:
- The average number of incorrect/”do not know” answers to the questions on FAV
- The proportion of respondents who know the correct amount of recommended FAV

The following variables/indicators will be used to assess the attitude towards FAV:
- The average scores on perceived barriers to FAV consumption
- The score on perceived benefits of FAV consumption
- The proportion of respondents who recognize all the benefits of FAV consumption
- The score on perceived susceptibility to FAV insufficient consumption

We plan to collect data on the knowledge scores among children remaining in the schools during the first semester of the new year (e.g. among risen 4th and 5th graders) to understand how much retention occurs.
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
We've described the experimental design above in the intervention component.
Experimental Design Details
Not available
Randomization Method
All randomization will be done using the statistical package Stata.
Treatment 1:
Out of 12 schools, 6 of them will have 2 grades who are in the treatment group, the other grade in the control group, and the other 6 will have 1 grade who is in the treatment group, the other 2 grades in the control group. The schools are first randomly paired up. Then, for each pair, 1 grade (out of 6 grades in total for 2 schools, e.g. grade 3 in school 1) is randomly selected to be treated. The other two grades in the same school (grade 4&5 in school 1) will be in the control group, while in the paired schools, the same grades (grade 4&5 in school 2) will be treated, the other grade (grade 3 in school 2) will be in the control group.

Once a grade is selected for treatment, all the classes within that grade will receive treatment.

Assuming each grade has a similar number of classes (5-6 classes per grade), in 12 schools there will be about 200 classes, half of which will be in the control group and the other in the treatment group.
This design has the following advantages: It is easier to convince the schools to treat one entire grade than some classes from different grade; besides, coming from different grades the children from the treatment group and control group are less likely to interact with each other, preventing diffusion of treatment.

Treatment 2:
Out of 6 pairs of schools, 1 of them is randomly selected to be treated. All the classes of the three grades in each of these 2 schools will be given fruits as snacks during the (morning) break.
Randomization Unit
Randomization of treatment 1 is done at the grade level. Randomization of treatment 2 is done at the pair of schools level.
Was the treatment clustered?
Yes
Experiment Characteristics
Sample size: planned number of clusters
Approximately 200 classrooms in 36 grades; for the longer recall endline (occurring in November 2019) we will lose the previous 5th graders and will be reduced to
Sample size: planned number of observations
10 children in each of the 200 classes, which corresponds to around 2000 children (and their parents) in total.
Sample size (or number of clusters) by treatment arms
Sample size (or number of clusters) by treatment arms
Treatment 1: 18 grades will be in the control group, 18 grades in the treatment group 1 (communication activities only),
Treatment 2: 10 schools in the control group, 2 schools (so 3 clusters out of 36 clusters) (communication activities and snack provisions) in the treatment group 2.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Power calculations were initially done using the clustersampsi command in Stata. The intra-cluster correlation was set at 0.1. The population mean was set at 119.5 grams of FAV per capita per day of consumption, standard deviation is set at 44.8 grams. These numbers were obtained from the Vietnam Household living Standard Survey 2014 data for observations in Dong Anh district. Significant level Alpha = 0.05 and Power Target = 0.8. The minimum detectable effect for the FAV consumption is estimated to be 13.1 grams (~0.3 SD). Revised power calculations were completed post-baseline and intracluster correlations were extremely low relative to expectations.
IRB
INSTITUTIONAL REVIEW BOARDS (IRBs)
IRB Name
International Food Policy Research Institute
IRB Approval Date
2018-12-01
IRB Approval Number
MTID-18-1260