Child survival and annual crop yield reductions in rural Burkina Faso: critical windows of vulnerability around early life development

Populations reliant on subsistence farming are particularly vulnerable to climatic effects on crop yields. However, empirical evidence on the role of the timing of exposure to crop yield deficits around early life development is limited. We examined child survival in relation to annual crop yield reductions at different stages around early life development in a subsistence farming population in Burkina Faso. Using shared frailty Cox proportional hazards models adjusted for confounders, we analysed 57,288 children <5 years of age followed by the Nouna Health and Demographic Surveillance System, 1992-2016, in relation to provincial food crop yield levels experienced in the following non-overlapping windows: 12 months before conception, in utero, birth-6 months, 6 months-2 years, 2-5 years of age; and their aggregates: birth-2 years, first 1,000 days since conception, birth-5 years. Of the non-overlapping windows, point estimates were largest for child survival related to yields for the time window of 6 months-2 years: adjusted mortality hazard ratio 1.10 (95% confidence interval 1.03 to 1.19) for a 90th to 10th centile yield reduction. These findings suggest that child survival in this setting is particularly vulnerable to cereal crop yield reductions during the period of non-exclusive breastfeeding.