Background The effects of economic downturns on population health in high-income countries have been well studied, but less so in low- and middle-income countries. We analysed how economic downturns affect child mortality both globally and among subgroups of countries of variable income levels.

Methods Economic and health data, and child mortality data was obtained from the World Bank and Institute for Health Metrics and Evaluation for 204 countries covering the years 1981–2010. We used multivariate regression models, to analyse the effect of changes in the growth rate of GDP on health child mortality, controlling for country-specific differences in healthcare infrastructure, population size and demographic structure, and using a dummy variable for economic downturns.

Results At the global level, downturns were associated with significant (p < 0.0001) deteriorations in child mortality: neonatal (coefficient: 1.11, 95% CI: 0.855, 1.37), post-neonatal (2.00, 95% CI: 1.61, 2.38), child (2.93, 95% CI: 2.26, 3.60) and under-5-years of age (5.44, 95% CI: 4.31, 6.58) mortality rates. Stronger (larger falls in the growth rate of GDP/capita), and longer (lasting two years rather than one) downturns were associated with larger, significant, deteriorations (p < 0.001). During economic downturns, countries in the poorest quartile experienced greater deteriorations in neonatal mortality (one-and-a-half-fold), post-neonatal mortality (three-fold), child mortality (nine-fold) and under-5-mortality (three-fold), than countries in the wealthiest quartile (p < 0.0005). For 1–5 years after downturns ended, each mortality measure continued to display significant deteriorations (p < 0.0001).

Conclusions Economic downturns occur frequently and are associated with significant deteriorations in child mortality, with worse declines in lower-income countries.