Use of peripherally inserted central catheters (PICCs) for intravenous antibiotics, infusion of chemotherapy or invasive hemodynamic monitoring has grown substantially in hospitalized patients. Although such use reflects advantages of PICCs (such as safer insertion in veins of the arm compared to veins of the neck or chest for conventional central venous catheters), not all PICCs are placed for appropriate reasons. Furthermore, PICCs are associated with important complications, including venous thromboembolism (VTE) and central line-associated bloodstream infection (CLABSI). Identifying and balancing the risks and benefits related to PICCs is critical to ensuring patient safety. The long-term objective of this study is to improve use and outcomes of PICCs across hospitals in the United States. Supported by funding from an AHRQ K award, the PI for this proposal developed the “Michigan Appropriateness Guide to Intravenous Catheters (MAGIC),” an evidence-based tool to inform and improve PICC use in hospital settings. This research project now aims to (a) implement MAGIC across 48-hospitals to determine whether it can improve appropriateness of PICCs; (b) evaluate whether improvements in PICC appropriateness are associated with fewer complications; and (c), identify what aspects of implementation at the hospital level led to the greatest change in appropriateness and complications. The study will leverage a large Blue Cross/Blue Shield of Michigan-funded collaborative quality improvement consortium: the Michigan Hospital Medicine Safety (HMS) consortium. Given a robust infrastructure for data collection and 48-member hospitals all actively engaged in improving PICC safety, HMS is the ideal setting to test MAGIC. Knowledge generated from this study will be seminal to making healthcare safer and understanding what provider and systems factors are associated with hospital performance – both priority areas for AHRQ. This project will be the first large scale implementation of a tool that has the potential to substantially improve the safety of thousands of patients that receive PICCs. Exceptional resources and team with extensive expertise in implementation science, patient safety and health services research make the University of Michigan an ideal environment for this proposal.