Public health in megacities and urban areas: Overall conceptual framework and some results from the megacity of Dhaka, Bangladesh

A growing number of megacities all over the world, particularly in developing countries, pose multidimensional challenges in many sectors including public health. Megacities are generally overburdened by a number of vulnerable groups of people (e.g. marginal settlers and unskilled migrants), often discriminated by political, educational, social, and health systems. Their poverty and limited income frequently force them to live in stressful conditions like slums, which are usually characterized by poor housing structures, overcrowding, tenure insecurity, insufficient safe drinking water, poor drainage, excessive open sewers and rubbish. However, the exact interplay of all these multi-level factors was not adequately studied and needs further investigation. This presentation will present a multidisciplinary conceptual framework for the study of public health issues in megacities as well as the necessity of multilevel analysis to test the developed framework. Moreover, we analysed epidemiological information of various sub-populations (n=2,222 adults, collected through a cross-sectional study) living in various slums and affluent areas of Dhaka megacity and its adjacent rural areas to estimate prevalence of various health outcomes (e.g. diseases) and their determinants. Results indicated that socio-demographic, housing and environmental characteristics differed significantly by the different sub-populations. Both bivariate and multiple logistic regression analyses indicated better health outcomes among rural inhabitants than those living in urban slums. Intra-urban differences were also documented. For instance, overweight and non-communicable diseases were more prevalent in the urban affluent population compared to the slum population, whereas the prevalence of underweight, communicable diseases, and fair/poor health status were higher among the population living in urban slums than those living in the urban affluent area. These findings will have implications for a better understanding of the complex population dynamics and mobility in megacity populations. Moreover, these findings will be helpful for public health interventions and health policy recommendations in urban settings.