Abstract
An estimatio of hospital care request of the resident population in the province of Bologna has been affected through the mapping, for geographical area of residence, of the discharges "consumed" from the citizens in quinquennium 1998-2002, analysed by nosological field and relevant pathologies. The clustering analysis has pointed out a strong correlation between respiratory apparatus diseases and circulatory system. Regarding thsi sector, which shows the greatest rate of hospitalisation (35.34 ‰ of residents), the cluster analysis has been carried out and three different clusters has been identified. Although the clusters were not linked by a prior assumptions, their use has allowed the localisation of unusual clusters, to be investigated by furhter specifics studies.