Enferm Infecc Microbiol Clin. 2013;31(Supl 4):16-24 0213-005X/$ - see front matter © 2013 Elsevier España, S.L. Todos los derechos reservados. Volumen 31, Extraordinario 4, Septiembre 2013 Enfermedades Infecciosas y Microbiología Clínica Programs to optimize the use of antimicrobials in hospitals (PROA): A Spanish initiative Enfermedades Infecciosas y Microbiología Clínica www.elsevier.es/eimc How to measure and monitor antimicrobial consumption and resistance Santiago Grau a,b,c, *, Germán Bou d,e , Esther Fondevilla f , Jordi Nicolás g , Manuel Rodríguez-Maresca h and Luis Martínez-Martínez i,j a Departamento de Farmacia, Hospital del Mar, Barcelona, Spain b Comité VINCat, Barcelona, Spain c Universitat Autònoma de Barcelona, Barcelona, Spain d Servicio de Microbiología, Complejo Hospitalario Universitario de A Coruña (CHUAC), A Coruña, Spain e Instituto de Investigación Biomédica de A Coruña (INIBIC), A Coruña, Spain f Centro Coordinador VINCat, Barcelona, Spain g Departamento de Farmacia, Hospital Son Llàtzer, Palma de Mallorca, Spain h Servicio de Microbiología, Hospital Complejo Hospitalario Torrecárdenas, Almería, Spain i Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla-IFIMAV, Santander, Spain j Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain Keywords: Antimicrobial consumption Defined daily dose Antimicrobial resistance Surveillance Bacterial fitness Palabras clave: Consumo de antimicrobianos Dosis diaria definida Resistencia a los antimicrobianos Vigilancia Coste biológico ABSTRACT Collateral damage caused by antibiotic use includes resistance, which could be reduced if the global inappropriate use of antibiotics, especially in low-income countries, could be prevented. Surveillance of antimicrobial consumption can identify and target practice areas for quality improvement, both in the community and in healthcare institutions. The defined daily dose, the usual adult dose of an antimicrobial for treating one patient for one day, has been considered useful for measuring antimicrobial prescribing trends within a hospital. Various denominators from hospital activity including beds, admissions and discharges have been used to obtain some standard ratios for comparing antibiotic consumption between hospitals and countries. Laboratory information systems in Clinical Microbiology Services are the primary resource for preparing cumulative reports on susceptibility testing results. This information is useful for planning empirical treatment and for adopting infection control measures. Among the supranational initiatives on resistance surveillance, the EARS-Net provides information about trends on antimicrobial resistance in Europe. Resistance is the consequence of the selective pressure of antibiotics, although in some cases these agents also promote resistance by favouring the emergence of mutations that are subsequently selected. Multiple studies have shown a relationship between antimicrobial use and emergence or resistance. While in some cases a decrease in antibiotic use was associated with a reduction in resistance rates, in many other situations this has not been the case, due to co-resistance and/or the low biological cost of the resistance mechanisms involved. New antimicrobial agents are urgently needed, which coupled with infection control measures will help to control the current problem of antimicrobial resistance. © 2013 Elsevier España, S.L. All rights reserved. Medición y monitorización del consumo de antibióticos y resistencias bacterianas RESUMEN El daño colateral más importante derivado del uso de los antibióticos es la aparición de resistencias bacte- rianas. La prescripción inadecuada de los antibióticos está íntimamente relacionada con este efecto, obser- vado globalmente a nivel mundial, pero principalmente en países con recursos económicos limitados. La estrecha vigilancia del consumo de los antibióticos puede ser de gran ayuda para identificar cuáles son los problemas relacionados con la prescripción de estos fármacos e introducir las estrategias necesarias para evitarlos, tanto en el ámbito ambulatorio como en el hospitalario. La dosis diaria definida, referida a la do- sis usual de un antimicrobiano concreto, destinada al tratamiento diario de un paciente, se ha considerado útil para el estudio de las tendencias de consumo de los antibióticos en el hospital. Esta unidad se ha intro- ducido en diversas fórmulas que incluyen diversos denominadores correspondientes a la actividad hospita- *Corresponding author. E-mail: sgrau@parcdesalutmar.cat (S. Grau).