Association of residential segregation and disability: a multilevel study using Iranian census data.

The association of racial segregation and health outcomes has been reviewed recently in the literature, but the health effect of other contexts of segregation with respect to residential environment has not as yet been fully reviewed. Besides, most of the literature on segregation has been performed in Western countries. Here, we undertake a multilevel analysis of residential segregation of socioeconomic and demographic factors and disability rate in an Eastern developing country in order to elucidate the effects of this aspect of segregation on disability rate. The latest Iranian national census in 2006 was used to measure segregation indices and perform the analysis. Information theory index and its ordinal form were applied to measure evenness dimension of segregation of categorical and ordinal variables, respectively. Segregation of contextual and structural characteristics of residential environment, which are important determinants of socioeconomic status in Iran, had different relations with disability rate. Provinces which were segregated by type of occupation of residents, sex, and ownership of a motorcycle had a lower individual disability rate, while age segregation and house ownership had a positive effect on the rate of individual disability in the province. The findings also showed that almost all the aforementioned segregation indices had the same effect on the rate of family disability. The unique contribution of this study is that it considers how segregation with respect to aspects of social characteristics other than race affects health outcomes. Further studies in this regard may reveal new insights into health outcome inequalities.