Studies of Birth-weight and Infant Mortality in India

BackgroundBirth-weight and infant mortality are both important indicators of the health of populations. Unfortunately, these measures have not been studied to a great extent in India, where high rates of both birth-weight and infant mortality persist. This is, in part due to a dearth of quality data from India and lack of methods to adjust the existing data for digit preference ("heaping"). Beyond that, while there has been extensive study of the birth-weight to infant mortality relationship in the developed world, this topic has remained basically unexplored in India. In order to develop methods to reduce the high rates of IM in India and better understand the role of birth-weight as a determinant of infant mortality, population specific studies are needed.MethodologyUsing data from a cohort in rural South India, we developed a method of adjusting BW data to account for heaping. Using data from a nationally representative survey of all of India, and US vital statistics, we compared characteristics of the BW to IM relationship in India and the United States. Finally, we analyzed data from rural India to identify predictors of very small birth-weight and infant mortailty in that specific population.ResultsOur method of adjusting birth-weight data to account for heaping using modified statistical calibration and multiple imputation produced imputed birth-weight data sets that reduced heaping and preserved known associations. After comparing the US and India, we found that the relative contribution of birth-weight to infant mortality in India is reduced. We also found differences between the US and Indian birth-weight distributions and infant mortality curves. Finally, we determined that measures of sanitation and hygiene, acting as surrogates for infectious disease exposure, were significant predictors of both lower birth-weight and infant mortality in a rural population in South India.ConclusionsWhile birth-weight and infant mortality have not been studied to a great extend in the developing world due to issues with data quality and sources, statistical methods can be used to address these issues. Being able to adjust birth-weight data and study it and infant mortality in an Indian population showed that characteristics of these measures are not the same across countries. Also, birth-weight may not be as important a factor in determining infant mortality in India as it is in the US. Therefore, finding other causes of infant mortality is extremely important to address this problem. To that end, we found that sanitation and hygiene are strongly associated with the high rates of infant mortality in a rural Indian population.Public Health SignificanceThe methods developed here can be used and applied to study birth-weight data in other developing country populations. The comparison of the US and India highlighted the fact that current policies to reduce infant mortality in India may be misguided. Finally, our data suggest that an intervention to improve sanitation and hygiene in order to reduce infant mortality could be successful and could also be used in other populations with high rates of infant death