Leaving no one behind: Assessing declines in early neonatal, late neonatal, post neonatal, and child mortality for the richest and poorest children in 38 low-and-middle-income countries.

The United Nations Sustainable Development Group suggests that the rate of decline should be the fastest among the most vulnerable to close equity gaps for goals aiming to zero. Using under-five deaths as a case study, this study highlights that target rates of decline should be disaggregated by dimensions of vulnerability within countries. In this study, we examine rates of change in the early neonatal, late neonatal, post neonatal, and child mortality periods in 38 countries using Demographic and Health Survey data. Overall, we find that in most countries, the rate of decline for the four outcomes was faster among the poorest children than the richest children. However, we show that in many countries, the poorest children in the most recent time point experience higher rates of death than the richest children in the earliest time point. Additionally, the poorest children are not on track to meet our proposed SDG targets despite experiencing faster rates of decline than the overall rate of decline. Our findings highlight the importance of establishing target rates of decline that are disaggregated by dimensions of vulnerability.