Background: Socio-economic and demographic determinants of child growth at ages 0–5 years in developing countries are well documented. However, Precision Public Health interventions and population targeting require more finely grained knowledge about the existence and character of temporal changes in child growth associations. Methods: We evaluated the temporal stability of associations between height-for-age z-score (HAZ) of children aged 0–59 months and child, parental, household, and community and infrastructure factors by following 25 countries over time (1991–2014) in repeated cross-sections of 91 Demographic and Health Surveys using random effect models and Wald tests. Results: We found that child growth displayed relatively more time stable associations with child, parental, and household factors than with community and infrastructure factors. Among the unstable associations, there was no uniform geographical pattern in terms of where they consistently increased or decreased over time. There were differences between countries in the extent of temporal instability but there was no apparent regional grouping or geographic pattern. The instability was positively and significantly correlated with annual changes in HAZ. Conclusions: These findings inform about the generalizability of results stemming from cross-sectional studies that do not consider time variation – results regarding effects of child, parental, and household factors on HAZ do not necessarily need to be re-evaluated over time whereas results regarding the effects of infrastructure and community variables need to be monitored more frequently as they are expected to change. In addition, the study may improve the Precision Public Health population targeting of interventions in different regions and times – whereas the temporal dimension seems to be important for precision targeting of community and infrastructure factors, it is not the case for child, parental, and household factors. In general, the existence of temporal instability and the direction of change varies across countries with no apparent regional pattern.
Bibliographical noteFunding Information:
Bill & Melinda Gates Foundation supported the research through a research grant to MR ( OPP1142342 ), and ST was supported through this grant.
This study was supported by the Bill & Melinda Gates Foundation. The article contents are the sole responsibility of the authors and may not necessarily represent the official views of the Bill & Melinda Gates Foundation. The research and co-author team were part of the Population and Surveillance Data Integration (PSDI) team of the Healthy Birth, Growth, and Development knowledge integration (HBGDki) initiative of the Bill & Melinda Gates Foundation (BMGF). The HBGDki aim of developing Precision Public Health motivated this analysis. The authors received valuable comments on drafts and presentations from Shasha Jumbe, Ted Grasela, Aryeh Stein, and Stef van Buuren. The authors are grateful to Elly Trepman for writing support and medical editing funded by BMGF; Matthew Sobek at Minnesota Population Center for assistance with data curation and harmonization supported through a grant from BMGF; two anonymous referees for their valuable comments. Last but not least we would also like to thank all members of the HBGDki community, which inspired us to do this research and provided feedback during team meetings, workshops, and presentations.
© 2019 The Authors