The physical expansion of the city of Ouagadougou, the capital and largest city of Burkina Faso, subsided in 2015 after the government banned land speculation that contributed to the growth and entrenchment of informal areas. The government subsequently implemented social policies such as free health care for pregnant women and children under 5 years of age. Against this background, we tested the convergence of under-5 mortality trends between formal and informal areas in the city between 2010 and 2019; data covering that period came from the Ouagadougou Health and Demographic Surveillance System (HDSS). The analyses included the calculation of all-cause and cause-specific mortality rates, the implementation of a Poisson regression model, and competing risk models. Over the study period, children in formal areas had lower mortality than those in informal areas. However, the inequality gap decreased over time due to a faster mortality decline in informal areas. This decline was explained by a rapid decline in deaths from malaria and other causes including sepsis, HIV/AIDS, measles, meningitis, and encephalitis. The pursuit of upgrading informal areas and the implementation of social policies targeting the poorest are likely to accelerate the mortality decline in Ouagadougou overall.

Under five mortality, Cause-specific mortality, Ouagadougou HEalth and Demographic Surveillance System, Free health policy, Informal areas