Exploring socio-demographic-and geographical-variations in prevalence of diabetes and hypertension in Bangladesh: Bayesian spatial analysis of national health survey data.

Bangladesh has been experiencing an epidemiological transition from communicable diseases to non-communicable disease (NCDs), with a rapid increase in the NCD related morbidity and mortality in the last decade. Hypertension and diabetes are two important risk factors of NCDs that significantly increase the burden of cardiovascular diseases and risk of death. While the prevalence of people with both hypertension and diabetes has been increasing dramatically over time, it is essential to identify relatively more prevalent socio-demographic groups and geographical regions (local administrative districts) to reduce the NCDs related deaths in an urgent basis. This study focused on examining the association of socio-demographic factors with both hypertension and diabetes and exploring the regional variations in their prevalence using nationally representative survey data on adult population of age over 35 years. Bayesian spatial analysis was performed for both hypertension and diabetes data separately by fitting a model, that accounts for spatial variations, using integrated nested laplace approximation. The area-specific prevalence was then estimated as weighted average of the corresponding individual level predicted probabilities of being diseased derived from the fitted model, with weight from the individual level sampling weight. Finally, the estimated area-specific prevalence estimates were sketched in country-map to explore regional variations and identify regions with relatively higher prevalence. The results revealed that people of older age, higher education, better socio-economic condition, higher BMI are at greater risk of having hypertension and diabetes. Significant regional variations were observed with prevalence for hypertension ranges between 10% and 35% and for diabetes between 6% and 19% while their national prevalence were reported as 24% and 11%, respectively. The western regions of the country including middle capital city were found to be relatively more prevalent for hypertension while the middle-east and south-east regions were observed to be more prevalent for diabetes. The capital Dhaka region was observed as the most prevalent for both diabetes and hypertension. Details explanations of the findings and evidence based policy implications were discussed.