Cause of death risk in relation to general mortality in zones with different degrees of urbanization.

This investigation deals with the distribution of mortality of four groups of causes (Diseases of the Circulatory System, of the Respiratory System, of the Digestive System, Injuries and Poisonings) in the coastal (urban area), hill (semi-urban area) and mountain (rural area) zones of the Marche (a region of Central Italy) with the aim of evaluating the risk of death from a specific cause in relation to mortality from all causes. Besides the Age Standardized Mortality Rates (ASDR), both the Relative Standardized Mortality Ratios (RSMR) and the Standardized Proportional Mortality Ratios (SPMR) were utilized.--The results obtained showed that the RSMR and the ASDR had the same trend when the urgan area and the rural area were compared--excluding the diseases of the circulatory system--the risk of death from causes was higher in the urban area. On the contrary, comparing the semi-urban area with the urban area and the rural area, dissonant behaviour between the two parameters was revealed.--The results obtained with the RSMR and with the SPMR were almost always similar.--To determine the significance of the deviation between expected number and observed number of deaths, the procedure for estimating the relation of mortality from specific causes to that from all causes (adaptation of Mantel-Haenszel method) was used. The deviation of the observed from expected number of deaths in the mountain zone, taking the coastal zone as control, was statistically significant or very close to significance for each cause with the exception of injuries and poisonings in females and diseases of the circulatory system in both sexes.