242. Evaluating the Effectiveness of Antimicrobial Restriction at an Academic Medical Center

Background Antimicrobial Stewardship Programs (ASPs) promote the optimal use of antimicrobial agents with the goal of preserving the effectiveness of existing drugs. One core ASP strategy is formulary restriction and preauthorization (PA). We evaluated restricted antimicrobial use at an academic medical center in Virginia; our program has a comprehensive restriction program that applies to adults only. Methods Data from August 2012 to June 2017 were evaluated at the hospital unit level by month in days of therapy (DOT) per 1,000 patient-days. Ordinary least squares regression was used to compare the time trend of restricted use with that of nonrestricted agents within the same unit. Results Across the study period significant decreases in restricted antibiotic use were detected for medical and pediatric units with no significant increases in use. However, significant increases were identified for surgical units. Table 1: Results of Time Trend Analysis by Unit for Restricted Drugs. Restricted Type Unit Time Trend P Medical Oncology 0.64 0.0924 Acute Care Medicine 0.39 0.4058 Cardiac ICU −0.37 0.1057 Medical ICU −2.06 0.0002 Bone Marrow Transplant 0.52 0.5002 Digestive Health −0.14 0.3004 Progressive Care −0.93 0.0002 Pediatric General Pediatrics −0.36 0.1363 Neonatal ICU −0.29 0.0007 Pediatric ICU −0.12 0.7849 Progressive Care −0.29 0.0993 Surgical Acute Care Surgery −0.30 0.1574 Burn ICU 0.84 0.0021 Cardiac Surgery ICU −0.50 0.2766 Surgical Trauma ICU −0.52 0.1019 Table 2: Significant Increases/ Decreases in Restricted Antimicrobials by Unit Type Restricted Unit Type Increase Decrease Medical 0/7 (0%) 2/7 (29%) Pediatric 0/4 (0%) 1/4 (25%) Surgical 1/4 (25%) 0/4 (0%) Conclusion These data suggest that the PA strategy for medical wards was effective across the time period whereas the PA strategy for surgical wards was suboptimal. However, it is unclear why pediatric wards (that were not subject to PA activities) also saw reductions in use; more research into this is needed. These data will help us to refine our PA strategy by targeting use on surgical wards. We believe that this type of analysis may be useful for other ASPs utilizing the PA strategy. Disclosures All authors: No reported disclosures.