Antibiotic diversity and bacterial resistance

Objective. To describe bacterial resistance as rates and proportions, describe the various measures of antibacterial use diversity and to examine any associations that may exist between diversity and resistance measures.; Methods. A retrospective, observational study design was used to describe the patterns of resistance and diversity of antibacterial use from 2002-2005 in a sample of UHC member hospitals. Relationships between resistance and diversity of antimicrobial use during a given year and across the study period were also analyzed.; Results. Different measures of both resistance and diversity are well correlated with one another. Significant associations between different measures of diversity and resistance appear throughout the study period depending on the year and measures used.; Conclusions. The true pattern, if one exists, between diversity and resistance remains unclear. This study provides evidence for future research of diversity and resistance to determine which mix of diversity is most associated with resistance.