Epidemiologic evidence for a potentiating effect of malnutrition on child mortality

Objectives. Despite broad agreement that severe malnutrition contributes to child mortality in developing countries and that malnutrition has a physiologically synergistic relationship with morbidity, evidence of an epidemiologic synergism has been lacking. Also, the literature provides conflicting evidence concerning the existence of elevated mortality among children with mild to moderate malnutrition. A review of published population-based studies of anthropometry-mortality relationships was undertaken to clarify these relationships. Methods. Six studies with the relevant data were reanalyzed to test for synergism and elevated mortality in mild to moderate malnutrition. Results. The results demonstrate that mortality increases exponentially with declining weight for age. This effect is consistent across studies and there is no apparent threshold effect on mortality. The primary difference across studies is in baseline levels of mortality, which determine the quantitative impact of malnutrition on mortality in a population. Conclusions. These results indicate that mild to moderate malnutrition is associated with elevated mortality and that there is an epidemiologic synergism between malnutrition and morbidity. This previously undemonstrated finding has significant implications for child survival policies and research.