Conventional methods of classifying causes of death suggest that about 70% of the deaths of children (aged 0-4 years) worldwide are due to diarrhoeal illness, acute respiratory infection, malaria, and immunizable diseases. The role of malnutrition in child mortality is not revealed by these conventional methods, despite the long-standing recognition of the synergism between malnutrition and infectious diseases. This paper describes a recently-developed epidemiological method to estimate the percentage of child deaths (aged 6-59 months) which could be attributed to the potentiating effects of malnutrition in infectious disease. The results from 53 developing countries with nationally representative data on child weight-for-age indicate that 56% of child deaths were attributable to malnutrition's potentiating effects, and 83% of these were attributable to mild-to-moderate as opposed to severe malnutrition. For individual countries, malnutrition's total potentiating effects on mortality ranged from 13% to 66%, with at least three-quarters of this arising from mild-to-moderate malnutrition in each case. These results show that malnutrition has a far more powerful impact on child mortality than is generally appreciated, and suggest that strategies involving only the screening and treatment of the severely malnourished will do little to address this impact. The methodology provided in this paper makes it possible to estimate the effects of malnutrition on child mortality in any population for which prevalence data exist.
PIP: Conventional methods of classifying causes of death suggest that about 70% of the deaths of children 0-4 years old worldwide are due to diarrheal illness, acute respiratory infection, malaria, and immunizable diseases. The role of malnutrition in child mortality is not revealed by these conventional methods, despite the long-standing recognition of the synergism between malnutrition and infectious diseases. This paper describes a recently-developed epidemiological method to estimate the percentage of child deaths (ages 6-59 months) which could be attributed to the potentiating effects of malnutrition in infectious disease. The methodology is based on the results of 8 community-based, prospective studies of the relationship between anthropometry and child mortality from the rural areas of Bangladesh, India, Indonesia, Malawi, Papua New Guinea, and Tanzania. These studies suggest that the risk of mortality increases at a compounded rate of 5.9% for each percentage point decline in weight-for-age below the reference point of 90% weight-for-age. Using the relative risk estimates, the standard epidemiological statistic of population-attributable risk (PAR) was used to estimate the percentage of child deaths attributable to malnutrition's potentiating impact on infectious disease. The results from 53 developing countries with nationally representative data on child weight-for-age indicated that 56% of child deaths were attributable to malnutrition's potentiating effects. 83% of these were attributable to mild-to-moderate as opposed to severe malnutrition, with a range of 73-74% in Bangladesh and India to a high of 100% in countries with very low malnutrition prevalences. For individual countries, malnutrition's total potentiating effects on mortality ranged from 13% in Paraguay to 67% in India, with at least 3/4 of this arising from mild-to-moderate malnutrition in each case. The powerful impact of malnutrition on child mortality suggests that strategies involving only the screening and treatment of the severely malnourished are not sufficient.