Health inequality in the tropics and its costs: a Sustainable Development Goals alert

BACKGROUND: It is known that health impacts economic performance. This article aims to assess the current state of health inequality in the tropics, defined as the countries located between the Tropic of Cancer and the Tropic of Capricorn, and estimate the impact of this inequality on gross domestic product (GDP). METHODS: We constructed a series of concentration indices showing between-country inequalities in disability-adjusted life years (DALYs), taken from the Global Burden of Disease Study. We then utilized a non-linear least squares model to estimate the influence of health on GDP and counterfactual analysis to assess the GDP for each country had there been no between-country inequality. RESULTS: The poorest 25% of the tropical population had 68% of the all-cause DALYs burden in 2015; 82% of the communicable, maternal, neonatal and nutritional DALYs burden; 55% of the non-communicable disease DALYs burden and 61% of the injury DALYs burden. An increase in the all-cause DALYs rate of 1/1000 resulted in a 0.05% decrease in GDP. If there were no inequality between countries in all-cause DALY rates, most high-income countries would see a modest increase in GDP, with low- and middle-income countries estimated to see larger increases. CONCLUSIONS: There are large and growing inequalities in health in the tropics and this has significant economic cost for lower-income countries.