Social and demographic determinants in the prescription of systemic antibiotics.

: Spain presents a high level of systemic antibiotic consumption and subsequently shows important rates of bacterial resistance. Diverse parameters explain the uneven distribution of their consumption such as the epidemiology of infectious processes, population-dependent factors, and factors dependent on the prescribing doctor. The aim of this study was to investigate demographic parameters that may affect antibiotic consumption. We carried out a retrospective longitudinal study from 2001 to 2005 on the basis of antibiotic consumption data provided by the information system of the drugstore Concylia. The consumption indicator used is the number of defined daily doses per 1000 inhabitants per day (DID). The area studied was the region of Castile and Leon, with nine provinces and eleven health districts. Global consumption per health district under study was as follows: Avila (22.37 DID), Zamora (21.83 DID), Salamanca (21.0 DID), Soria (20.67 DID), Palencia (18.97 DID), Leon (17.56 DID), Burgos (16.59 DID), Segovia (16.50 DID), East Valladolid (16.36 DID), The Bierzo (16 DID) and the lowest consumer, West Valladolid (13.46 DID). Different patterns of consumption were found in the study period, according to the variability of infectious diseases and demographic factors such as population age and population density. Significant area-dependent global consumption differences were observed in relation to acute respiratory infections and population-dependent factors. The differences were more marked when studying the geographical distribution of the consumption of the principal active ingredients.