<qa>  What is the study hypothesis that the preauthorization group will impact on a reduction in antiThe study hypothesis is that the preauthorization group will impact on a reduction in antimicrobial cost and utilization, especially in the first 72 hours, when compared to prospective audit. However, patient outcomes will likely be similar. Antimicrobial stewardship programs using preauthorization as a core strategy compared to prospective audit with feedback have similar patient outcomes, but may reduce antimicrobial utilization. 