estimation of life expectancy and its association with social determinants of health (sdh) in urban population of different districts of tehran in 2008

introduction among the available data provided by health information systems, data on mortality are commonly used both as health inequality indicators and also socioeconomic development indices. mortality rates and life expectancy are considered as the key components of the health inequalities worldwide. till now, socioeconomic inequalities in total life expectancy have been mostly well documented in the level of countries or even continents and it is not generally assessed at the level of a single city area. the city of tehran has traditionally been divided geographically into various districts with differences in socioeconomic status and some other indicators. therefore, we aimed to estimate life expectancy and to evaluate the effects of social determinants of health (sdh) on it in different districts of tehran as a huge hierarchical metropolitan. methods & materials this analytical cross-sectional study was performed during the year 2008 via the project tehran urban heart study. during august till november 2008, an approximate number of 1000 families in each 22 districts of tehran -totally 22492 households- including 81665 persons were recruited following random stratification. after appropriate revising following the performance of pilot study, the study questionnaire was consisted of a 13 pages checklist having several questions about demographic characteristics, socioeconomic indicators, job category, house of residency, level of literacy, and etc. moreover, sufficient data on any mortality (including age and sex) in each household during the year 2008 was recorded. life tables were extracted using lifetab excel software also spss v.17 and stata v.10 were used to perform ecologic and concentration (individual level) analysis, respectively. results overall life expectancy (le) was calculated as 77.98 (95% ci: 75.50-78.69) yr which was significantly higher among women [79.96 (95% ci: 77.79-82.13) yr vs. 74.53 (95% ci: 72.22-76.85) yr, p<0.05] than men. the highest le was observed in the east (81.64 yr) and north (79.43 yr) of tehran while the south region with le of 74.38 yr had the lowest. analytical procedures show that mortality was significantly more concentrated in families with lower total non-food costs (concentration index= -0.1599, p<0.0001) and lower level of education (concentration index= -0.1770, p<0.0001). moreover, in ecologic data analysis, le had significantly direct correlation with total non-food costs (r= +0.695, p<0.001), costs per capita (r= +0.553, p=0.009) and frequency of social class 1 or sc-1 (r= +0.437, p=0.030) while it was reversely correlated with family size (r= -0.486, p=0.025) and frequency of sc-5 (r= -0.476, p=0.029). conclusion although the estimated life expectancy was higher in tehran in comparison with the other estimations of the country, considerable differences were observed between regions and districts of this city. socioeconomic status and the level of education were among the most important sdh&aposs; influencing mortality rates and le in tehran which was significantly different from a region to another one. conclusively, geographical inequalities in mortality and socioeconomic status are shown to exist in tehran area in this study and this finding emphasized on the need of more attention from policy makers of different disciplines including various ministries and tehran municipality.