Antimicrobial drug use in hospitalized children

The discovery of antibiotics represents one of the milestones in modern medicine and has since the beginning of the 20th century made a major contribution to the reduction in mortality and morbidity from infectious diseases. The shadow side of their success is antimicrobial drug resistance which is a great threat to public health. The reasons for the rise in antimicrobial resistance are manifold and complex, but it has become clear that excessive and indiscriminate use of antibiotics increase the risk of selection of and emergence of antimicrobial resistant organisms. The resistance problem along with a nearly empty pipeline of innovative antimicrobial agents emphasizes the importance of appropriate use of the available antibiotics. Valid quantitative and qualitative data on the use of antibiotics in hospitals are necessary to detect patterns of potentially inappropriate use and to evaluate strategies to contain antimicrobial resistance. Antimicrobial agents are among the most frequently used drugs in neonatal intensive care units (NICUs), since the multiple risk factors for infection and the severe consequences thereof in preterm immunocompromised infants result in a low threshold for the initiation of antimicrobial therapy. The general aim of this thesis is to describe patterns of antibiotic use in hospitals, predominantly in neonates, to establish valid measures thereof and describe its clinical consequences. This thesis consists of two parts. In the first part, studies describe the methodological aspects of measuring antibiotic use in hospitals. Although, it sounds rather simple to measure antibiotic use, one has to recognize several methodological issues, which will be described in this chapter. In the second part, studies describe the patterns and consequences of antibiotic use in hospitalized patients. Trends in antibiotic use were analyzed at different levels: at national, hospital and specific patient group (i.e. neonates) level. In the last chapter the key findings of the studies in this thesis are discussed in a broader perspective, focusing on two main topics namely ‘measuring antibiotic use in hospitals’ and ‘variability in antibiotic use’. We conclude with implications for clinical practice and perspectives for future research. In conclusion, in this thesis we presented several methodological challenges in measuring antibiotic use in hospitals and hospitalized children. Moreover, our results of monitoring antibiotic use in hospitals and hospitalized children showed clear variability in total antibiotic use, which is potentially worrisome. Global threats, such as multidrug resistance and a nearly empty pipeline of new antibiotics, emphasizes the importance of appropriate antibiotic use. Therefore, we should recognize the enormous impact of inappropriate antibiotic use and tackle this global rising problem.