Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 42 12 2013 12 15 1354 62 Md Nazrul Islam Mondal 1. Laboratory of Computational Statistics and Operations Research, Institute for Mathematical Research University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan , Malaysia ; 2. Dept. of Population Science and Human Resource Development; University of Rajshahi , Rajshahi, Bangladesh. Mahendran Shitan 1. Laboratory of Computational Statistics and Operations Research, Institute for Mathematical Research University Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan , Malaysia ; 3. Dept. of Mathematics, Faculty of Science, University Putra Malaysia; 43400 UPM Serdang, Selangor Darul Ehsan , Malaysia. 2015 10 15 This study is concerned with understanding the impact of demographic changes, socioeconomic inequalities, and the availability of health factors on life expectancy (LE) in the low and lower middle income countries.The cross-country data were collected from 91 countries from the United Nations agencies in 2012. LE is the response variable with demographics (total fertility rate, and adolescent fertility rate), socioeconomic status (mean year of schooling, and gross national income per capita), and health factors (physician density, and HIV prevalence rate) are as the three main predictors. Stepwise multiple regression analysis is used to extract the main factors.The necessity of more healthcare resources and higher levels of socioeconomic advantages are more likely to increase LE. On the other hand, demographic changes and health factors are more likely to increase LE by way of de-cease fertility rates and disease prevalence.These findings suggest that international efforts should aim at increasing LE, especially in the low income countries through the elimination of HIV prevalence, adolescent fertility, and illiteracy. https://ijph.tums.ac.ir/index.php/ijph/article/view/4283 https://ijph.tums.ac.ir/index.php/ijph/article/download/4283/3935