On sustainability of correlation in deaths for twins aged under five -- a population-based study in Matlab Bangladesh.

This population-based study provides an empirical evaluation on the sustainability in the correlation of deaths in twins aged less than 5 years in Matlab Bangladesh. Data on 593 twin pairs with both infants born alive identified from the Demographic Surveillance System during 1977-85 were analyzed. Results showed that deaths among twin pairs were correlated decreasingly with the age of the children. An improved survival pattern of the index twin with higher surviving ages of the co-twin (P < 0.0001) was observed and the correlation of joint survival status in the pairs was estimated. Using a generalized estimation technique correlation was adjusted for the effects of some dominant biosocial indicators while estimating the linear logistic regression model for marginal probability of survival of individual twins. A pattern of decreasing correlation was noted: adjusted correlation was the highest at 0.60 for the first 24 hours of life fell to 0.21 after the neonatal period declined further to 0.11 after age 6 months and mostly disappeared at the age of 1 year. An explanation of the pattern relates to the dying out of frail twins and increasing survival potential for sturdy ones who remain. In conclusion the study supports the recommendation for special health care and monitoring facilities for twins at least for the first year of life in developing countries.