The Effects of Meteorological Factors on Mortality: Evidence from Two Health and Demographic Surveillance Sites in Bangladesh, 1983-2009

Context: Bangladesh is divided into seven distinct climatic zones. The effect of climate on mortality can be different in different zones. This study aims to assess the weather-mortality relationships in two climatic zones.
Methods: Health and demographic surveillance sites (HDSS) maintained by icddr,b in Matlab and Abhoynagar in two climatic zones provided daily counts of death and population during 1983-2009. Weather data on daily temperature and rainfall and cyclones for the same period were obtained from nearby weather stations of the Bangladesh Metrological Department. Time series Poisson regression with cubic spline functions, was used allowing for over dispersion and lagged effects of weather on mortality, controlling for time trends and seasonal patterns. Analysis was carried out using R statistical software.
Findings and conclusions: Both temperature and rainfall showed strong seasonal patterns, explaining a significant part of mortality in both sites. Abhoynagar with more extreme in temperature exhibited stronger cold temperature-mortality relationship than Matlab. Abhoynagar with less rainfall exhibited the rainfall-mortality association, which was not the case with Matlab. The weather-mortality relationships by age, sex and broad cause were also examined to identify vulnerable groups and areas.