PROJECT SUMMARY Background: Antibiotic overuse results in antimicrobial resistant (AMR) bacteria and unnecessary adverse events including Clostridioides difficile infections (CDI) killing up to 150,000 and specifically 29,000 Americans. Without intervention these numbers are likely to increase. Surgical antibiotic prophylaxis is a common area for unnecessary antibiotic use among hospitalized children following life-saving surgery. The CDC surgical site infection (SSI) guidelines and the AAP Choosing Wisely Campaign recommend no postoperative antibiotic prophylaxis for procedures considered low risk for an SSI. Our current stepped-wedge cluster randomized trial shows antimicrobial stewardship program (ASP) teams participating in a facilitation workshop significantly reduced inappropriate post-operative antibiotic use at the hospital level. Goal: To disseminate our virtual facilitation workshop to ASP teams and surgeons at 20 US children’s hospitals to aid to de-implement unnecessary postoperative antibiotic use in children while assessing important implementation and clinical outcomes. Methods: For Aim 1, we will adapt our current theoretically and evidence-based facilitation strategy, a problem-solving approach to integrating evidence-based care, with feedback we received from current study participants and updated scientific literature for synchronous and asynchronous online workshop. For Aims 2 and 3, we will recruit 20 children’s hospitals that are members of both the SHaring Antimicrobial Reports for Pediatric Stewardship (SHARPS) Collaborative and the National Surgical Quality Improvement Program- Pediatric (NSQIP-P). ASP teams and their surgeon champions will participate in the updated facilitation workshop. Individuals participating in the workshop will complete pre/post surveys and interviews to assess the immediate and long-term implementation outcomes including feasibility, appropriateness, guideline integration through order set changes, and reach across surgical subspecialities (Aim 2). Each children’s hospital will provide NSQIP-P clinical data three years pre- (2022-2024) and post-intervention (2025-2027). Utilizing these data, a time-series analysis will evaluate the impact of the intervention on appropriate post-operative antibiotic use and the rate of SSI and CDIs (Aim 3). Innovation and Impact: This study is innovative and impactful because it will: 1) combine expertise from surgeons, antimicrobial stewards and implementation scientists to disseminate an effective de-implementation strategy to eliminate unnecessary antibiotic use; 2) assess the impact of this strategy on surgeries in children, an underrepresented group; 3) utilizing a time-series analysis, clinical outcomes (e.g. antibiotic use, SSI, CDI) important to ASPs and surgeons will be evaluated; 5) collect implementation outcomes that will inform the dissemination of the strategy to more hospitals; and 6) synergy between two large collaboratives (SHARPS & NSQIP) that wi...