Measuring Appropriate Antimicrobial Use: Attempts at Opening the Black Box.

Indiscriminate antimicrobial use has plagued medicine since antibiotics were first introduced into clinical practice >70 years ago. Infectious diseases physicians and public health officials have advocated for preservation of these life-saving drugs for many years. With rising burden of antimicrobial-resistant organisms and Clostridium difficile infections, halting unnecessary antimicrobial use has become one of the largest public health concerns of our time. Inappropriate antimicrobial use has been quantified in various settings using numerous definitions; however, no established reference standard exists. With mounting national efforts to improve antimicrobial use, a consensus definition and standard method of measuring appropriate antimicrobial use is imperative. We review existing literature on systematic approaches to define and measure appropriate antimicrobial use, and describe a collaborative effort at developing standardized audit tools for assessing the quality of antimicrobial prescribing.