Effect of the population in collective dwellings on small-area mortality risk estimation in the Basque Country region (Spain)

Abstract

Objective: To quantify the effect of the inclusion of the population in collective dwellings on the estimation of mortality risk in the census areas of the Basque Country (Spain) for the main causes of mortality in the period 1996-2003. Method: Small-area ecological cross-sectional study. The main causes of mortality by sex were analyzed. Results: When the general effect on all areas with a a population in collective dwellings was analyzed, hardly any noticeable effect was seen on either men or women. On the other hand, an effect was found when selecting the areas where the population in collective dwellings is more than 10% of the area's population. Conclusions: The effect of the inclusion of the population in collective dwellings clearly seen in causes of mortality, such as dementia and Alzheimer's disease, and in chronic obstructive pulmonary disease, related to greater dependence or frailty, and therefore related to being in a nursing or elderly persons’ home, over-estimating the risk of mortality by approximately 8% and 4%, respectively, in these geographical areas.