Although there is great experience in the study of mortality inequalities in Spanish cities, there are still large urban centers that have not been analyzed using the census section as a unit of territorial analysis. This is the context of the coordinated MEDEA Project “Socioeconomic and Environmental Health Inequalities in Catalonian Cities (Desigualdades socioeconómicas y medioambientales en salud en ciudades de Cataluña)”, in which ten groups of researchers from Andalusia, Aragon, Catalonia, Galicia, Madrid, Valencia, and the Basque Country are participating.
Four particularities should be noted: a) the census section is used as the basic geographical area; b) statistical methods that take into account the geographical structure of the studied region are used for the risk estimation; c) the opportunities offered by three complementary data sources are exploited (information on air pollution, information on industrial pollution, and mortality records); and, d) a coordinated analysis is undertaken at a large scale, favored by the implementation of thematic research networks.
The aim of this study was to explain the methods used to smooth mortality indicators in the MEDEA Project. The study article focuses on the methodology and the results of the Besag-York-Mollié (BYM) disease map.
Although the standardized mortality ratios (SMRs) corresponding to seventeen large groups of mortality causes and 28 specific causes were smoothed in the project using the BYM model, in this study we applied this methodology to mortality from tracheal, bronchial, and lung cancer in both sexes in the city of Barcelona throughout the 1996-2003 period.
As a result, a different geographical pattern can be seen in the smoothed SMRs in both sexes. The SMRs observed among men living in neighborhoods with greater socioeconomic deprivation were greater than one. In women, this pattern was observed in areas with a greater socioeconomic level.
This was the first study in Spain and one of the first worldwide to use the Besag‑York‑Mollié spatiotemporal modeling method.