A Trend Study of Preterm Infant Mortality Rate in Developed and Developing Countries over 1990 to 2017

Background: Preterm birth is the most important in children under 5 yr mortality. In this study, we used the Global Burden of Disease Data (GBD) to evaluate the trend of preterm infant mortality rate for all countries from 1990 to 2017 and to assess the effect of development factors on this trend. Methods: The preterm infant mortality rate data from 196 countries of the world, from 1990 to 2017, were extracted from the GBD database. To study the trend of preterm infant mortality rate, a mixed-effects log-linear regression model was fitted separately for each IHME super-region. In the next step of data analysis, the devel-opment factor was included in the model to determine its effect on this trend for all countries under study. Results: The average rate mortality rate has declined about 2% per year throughout the world over the men-tioned period. The highest and lowest decreasing trends were observed in high-income countries (about 4.0%) and Sub-Saharan Africa (about 1.0%), respectively. Including the effect of development factor in the mentioned model revealed that in 1990, the rate of preterm infant mortality in developed countries was 2.2 times of this rate in developing countries and this rate ratio has increased to 2.69 in year 2017. Conclusion: Although the preterm infant mortality rate were decreasing in all super regions, there is a remark-able gap in this rate between developing and developed countries yet. Therefore, preventative strategies are needed to reduce preterm birth and its burden, especially in the developing world.