Longitudinal data analysis of data on outpatient antibiotic use in Europe

Abstract

Antibiotics are drugs used to treat bacterial infections. The use and misuse of antibiotics has over time lead to resistance of bacteria to several antibiotics. As a start to face this problem trustworthy information related to antibiotics consumption needs to be gathered. In this study the IMS Health data, expressed in both DID and PID and measured from 2000 until 2008, were used to analyze the global trend and seasonal fluctuations in antibiotic consumption. Nonlinear mixed models were constructed assessing both the change of antibiotic consumption over time and the change in seasonal fluctuation. To assess whether both models were in agreement a joint nonlinear mixed model was built containing information on both DID and PID. The change in DDD per package over time was assessed through a linear mixed model.