Can accurate data on birthweight be obtained from health interview surveys?

Background Because hospital records rarely exist for a representative sampl e of the population in developing countries, researchers frequently rely on birthweight data from surveys. Yet, the quality of these data has rarely b een evaluated. This study explores the accuracy of birthweight information in six demographic and health surveys in Latin America conducted in the ear ly 1990s: two in Guatemala, and one each in Bolivia, Costa Rica, Fl Salvado r and Peru. Methods The quality of the birthweight reports is assessed by examining the plausibility of estimates of the proportion of newborns reported to have b een weighed and estimates derived from the numerical weights, by characteri stics of the delivery and maternal education. Results The estimates suggest that a substantial proportion of women whose newborns were probably never weighed report a birthweight. For all of the s urveys, with the possible exception of Costa Rica, the average birthweights appear to be too high, and the estimates of the prevalence of low birthwei ght too low. In addition, the data reveal anomalous patterns, such as highe r birthweights for home as compared with hospital deliveries. Conclusions These findings suggest that estimates of low birthweight derive d from surveys in developing countries are likely to portray an overly opti mistic picture of children's and women's health status. More information ab out the underlying source of these data are needed not only to provide addi tional insight into the degree of error characterizing existing estimates, but also to improve data collection strategies in future health interview s urveys.