Association between economic growth, coverage of maternal and child health interventions, and under-five mortality: a repeated cross-sectional analysis of 36 sub-Saharan African countries

Infant and child mortality rates are among the most important indicators of child health, nutrition, implementation of key survival interventions, and the overall social and economic development of a population. In this report, using data from 99 Demographic and Health Surveys (DHS) conducted in 36 sub-Saharan African countries, we investigate factors that have contributed to the declines in under-five mortality rates (U5MR) in sub-Saharan Africa. Specifically, we focus on the extent to which changes in country-level economic growth and changes in the coverage of key maternal, neonatal, and child health (MNCH) interventions have contributed to reductions in under-five mortality. For this analysis we constructed two distinct data structures: (1) an ecological time series (with countries repeatedly observed) and (2) a multilevel repeated cross-section (which in addition took account of the variability between children within a country at any time). We employed a country-level fixed effects regression to model changes in U5MR across survey periods as a function of changes in economic growth and coverage of MNCH interventions for ecological time series data. The multilevel repeated cross-sectional data was used to examine the probability of a child being reported to have died at age 0-59 months, corresponding with different levels of economic growth and coverage, while accounting for within-country between-child factors that could influence both child mortality and the country-level economic development and coverage indicators. Our results show that changes in country-level per capita GDP (pcGDP) are not consistently associated with a reduction in U5MR across different model specifications. In ecological time series models, a unit increase in pcGDP is associated with a reduction in U5MR of 11.6 deaths per 1000 live births (95% CI: -29.1, 5.9), while a composite index of MNCH interventions is associated with a reduction in U5MR of 31.9 deaths per 1000 live births (95% CI: -48.6, -15.3). The results of the multilevel repeated cross-section data structure suggest that MNCH coverage indicators are important. For example, pcGDP is associated for a decreased likelihood of child mortality with an odds ratio of 0.96 (95% CI: 0.92 -1.00) and an increase of 1 standard deviation in the composite coverage index (CCI) is also associated with a decrease in child mortality [odds ratio 0.92 (95% CI: 0.88 - 0.96)]. A measure of improvements in sanitary facilities is associated with an odds ratio of 0.57 (95% CI: 0.50-0.65) for child mortality. Together, these results indicate that MNCH interventions are important in reducing U5MR, while the effects of economic growth in sub-Saharan Africa remain weak and inconsistent. Sub-Saharan Africa continues to have the highest U5MR globally, and progress toward reducing mortality rates has been slow. Our findings indicate that improved coverage of proven life-saving interventions and access to clean water and sanitation will likely contribute to further reductions in U5MR in sub-Saharan Africa in the future.