Changes in Underlying Determinants Explain Rapid Increases in Child Linear Growth in Alive & Thrive Study Areas between 2010 and 2014 in Bangladesh and Vietnam1,2,3
- Phuong Hong Nguyen4,*,
- Derek Headey4,
- Edward A Frongillo5,
- Lan Mai Tran6,
- Rahul Rawat4,
- Marie T Ruel4, and
- Purnima Menon4
- 4Poverty, Health, and Nutrition Division, International Food Policy Research Institute, Washington, DC;
- 5Department of Health Promotion, Education, and Behavior, University of South Carolina, Columbia, SC; and
- 6FHI 360, Hanoi, Vietnam
- ↵*To whom correspondence should be addressed. E-mail: p.h.nguyen{at}cgiar.org.
Abstract
Background: Child linear growth sometimes improves in both intervention and comparison groups in evaluations of nutrition interventions, possibly because of spillover intervention effects to nonintervention areas or improvements in underlying determinants of nutritional change in both areas.
Objective: We aimed to understand what changes in underlying socioeconomic characteristics and behavioral factors are important in explaining improvements in child linear growth.
Methods: Baseline (2010) and endline (2014) surveys from the Alive & Thrive impact evaluation were used to identify the underlying determinants of height-for-age z scores (HAZs) among children aged 24–48 mo in Bangladesh (n = 4311) and 24–59 mo in Vietnam (n = 4002). Oaxaca-Blinder regression decompositions were used to examine which underlying determinants contributed to HAZ changes over time.
Results: HAZs improved significantly between 2010 and 2014 in Bangladesh (∼0.18 SDs) and Vietnam (0.25 SDs). Underlying determinants improved substantially over time and were larger in Vietnam than in Bangladesh. Multiple regression models revealed significant associations between changes in HAZs and socioeconomic status (SES), food security, maternal education, hygiene, and birth weight in both countries. Changes in HAZs were significantly associated with maternal nutrition knowledge and child dietary diversity in Bangladesh, and with prenatal visits in Vietnam. Improvements in maternal nutrition knowledge in Bangladesh accounted for 20% of the total HAZ change, followed by maternal education (13%), SES (12%), hygiene (10%), and food security (9%). HAZ improvements in Vietnam were accounted for by changes in SES (26%), prenatal visits (25%), hygiene (19%), child birth weight (10%), and maternal education (7%). The decomposition models in both countries performed well, explaining >75% of the HAZ changes.
Conclusions: Decomposition is a useful and simple technique for analyzing nonintervention drivers of nutritional change in intervention and comparison areas. Improvements in underlying determinants explained rapid improvements in HAZs between 2010 and 2014 in Bangladesh and Vietnam.
Footnotes
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↵1 Supported by the Bill & Melinda Gates Foundation and CGIAR Research Program on Agriculture for Nutrition and Health. This is an open access article distributed under the CC-BY license (http://creativecommons.org/licenses/by/3.0/).
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↵2 Author disclosures: PH Nguyen, D Headey, EA Frongillo, LM Tran, R Rawat, MT Ruel, and P Menon, no conflicts of interest.
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↵3 The Bill & Melinda Gates Foundation and Alive & Thrive participated in the study design choices but not in collecting or analyzing data. Both gave extensive feedback at all stages of the project, but freedom to publish the study findings was protected contractually in the agreement between the respective funding sources and the International Food Policy Research Institute. All final decisions were made by the researchers.
- Manuscript received: November 7, 2016.
- Initial review completed: December 7, 2016.
- Revision accepted: January 3, 2017.
This is an open access article distributed under the CC-BY license (http://creativecommons.org/licenses/by/3.0/).
