Spatial relationship between dwelling crowding and selected causes of morbidity in Sydney, Australia, 1994-97

The environment in which we live greatly influences our health. One particu lar factor that has been related to morbidity and mortality is dwelling cro wding. A range of mechanisms have been proposed as links between dwelling c rowding and disease, including increased exposures to allergens, respirator y irritants and infectious agents in crowded dwellings. While studies of dw elling crowding have been conducted in many locations around the world, thi s factor has received little attention in Australian health studies. We exa mine relationships between dwelling crowding and health in Sydney, using th ree case studies at the local government area (LGA) level within the Sydney Statistical Division. Dwelling and demographic data from the 1996 Australi an census are used, along with four socio-economic indexes produced by the Australian Bureau of Statistics, and hospital inpatient data for the period 1 July 1994 to 30 June 1997 as the health indicator. Results suggest that dwelling crowding is a significant factor in certain diseases in Sydney. As thma hospital separations are not correlated with dwelling crowding, althou gh multiple linear regression analysis produces three models which include crowding and three of the socio-economic indexes as significant variables. Separations for bronchitis and emphysema, and all causes combined, are posi tively correlated with dwelling crowding. Dwelling crowding is strongly neg atively correlated with all but one of the socio-economic indicators.