The rise of antibiotic resistance is widely acknowledged to be an increasing threat to global public health. Promoting rational antibiotic prescribing patterns is one important approach to counter this development. Comprehensive analysis of patterns of antibiotic utilization and its quality in routine care is a perquisite to the design of effective tailored interventions to promote rational and judicious antibiotic prescribing. Automated health care databases facilitate the analysis of antibiotic utilization in outpatient care in large populations and can be used for international comparison of prescribing habits. In the German health care setting administrative databases of statutory health insurance companies (SHIs) capture all outpatient dispensations of prescription drugs and allow for the population-based and detailed analysis of antibiotic use in primary care. This doctoral thesis is based onone study on paediatric antibiotic use in German primary care and two studies comparing outpatient prescribing of systemic antibiotics to children and adolescents in the age group 0-18 years between Denmark, Italy, Germany, the Netherlands and the UK. These publications are complemented by a systematic review on the effectiveness of computer-aided clinical decision support systems in strengthening rational outpatient antibiotic prescribing. Here the aim is to (1) to further explore the significance of the published results in the light of the current state of research and (2) to amplify the discussion of important methodological issues and limitations. This comprises a critical review of the strengths and weaknesses of administrative data of German SHIs and comparable European databases as a basis for population-based studies of outpatient antibiotic utilization and cross-national comparison between European countries. In addition, an overview of the current state of knowledge regarding interventions to foster rational and judicious outpatient antibiotic prescribing is given and specific methodological challenges of the synthesis of evidence in this field are discussed. By allowing detailed cross-national comparisons of age- and gender-specific measures of antibiotic use, administrative data from German SHIs and similar European health care databases close an important gap in the surveillance of outpatient patterns of antibiotic use and the assessment of prescribing quality. Additional research is warranted to assess the validity of disease-specific measures of use based on German SHIs data. In recent years outpatient antibiotic use decreased in Germany, most remarkably in the paediatric setting. Nevertheless, further room for improvement exists. In particular, this concerns relatively high prescribing of broad spectrum agents as first line treatment of seasonal respiratory infections. Notably higher prescribing in contrast to other European countries such as the Netherlands, Denmark, Sweden or the UK can be seen for chinolones, cephalosporines (2nd and 3rd generation) and new macrolides. So far, a large number of international studies has been published aiming to improve quality of outpatient antibiotic prescription, mostly showing marginal to moderate intervention effects. Nevertheless, a selection of recently published studies consistently shows favourable effectiveness for some types of intervention, including the use of specific point-of-care tests
