Long-Term Trends in Seasonality of Mortality in Madagascar: The Role of the Epidemiological Transition

Benjamin-Samuel Schlüter, Louvain University (UCL)
Bruno Masquelier, Louvain University (UCL)
Jessica Metcalf, Princeton University
Anjarasoa Rasoanomenjanahary, Bureau Municipal d'Hygiène de la commune urbaine d'Antananarivo

Based on deaths registers maintained by the Municipal Hygiene Office from Antananarivo, this study assesses seasonal patterns and its changes over the period 1976-2015 of all-cause and cause-specific mortality by age groups, using Generalized Additive Mixed regression models. Among children, risks of dying were the highest during the hot and rainy season, but the seasonality in child mortality significantly reduced since the mid-1970s, due to declines in the burden of infectious diseases and nutritional deficiencies. In adults aged 60 and above, all-cause mortality rates are the highest in the dry and cold season, due to peaks in cardiovascular diseases, with little change over time. Changes in the seasonality within broad categories of causes of death have been modest. To conclude, shifts in disease patterns brought by the epidemiological transition, rather than changes in seasonal variations in cause-specific mortality, are the main drivers of trends in the seasonality of all-cause mortality.