There has been a long interest in public health on the linkage between health and socio-economic determinants, with many studies published from developed countries, for example in Europe and USA (Braveman and Tarimo 2002; Wagstaff 2000; Black et al. 2003). The studies commissioned by World Health Organization (WHO) on socio-economic determinants of health also spells out the importance of socio-disparities in health, and its impact on socio-economic development (Wagstaff 2000; Zere and McIntyre 2003). In these studies, the following have been identified as key determinants of health: deprivation or SES, education, race or ethnicity, and rurality. For years, routine public health statistics have been reported, in Europe and United states, by social factors (mainly income and education), race or ethnicity. These have facilitated monitoring of socio-economic disparities in health, and allowed comparison among social classes. In contrast, in developing countries, studies that examine differences in risk, stratified by education or income are relatively few, and where these have been considered there is no explicit investigation of socio-economic patterning (Fotso et al. 2005; Hong 2007).