BackgroundGuidelines for antimicrobial prophylaxis in surgery recommend cefazolin dose be adjusted based on patient weight. Adults weighing ≥120 kg should receive a 3 g dose, all other adult patients should receive a 2 g dose pre-operatively. To promote guideline adherence, an antimicrobial stewardship pharmacist-driven dose optimization intervention was implemented.MethodsRetrospective, pre (February 1, 2017–March 31, 2017)/post (February 1, 2018–March 31, 2018) study evaluating the impact of a pharmacist-driven cefazolin dose optimization intervention at a large health system. An alert within the electronic health record notified pharmacists during order verification when cefazolin dose from a surgical prophylaxis order set did not match weight-based recommendations. All patients with cefazolin orders for surgical prophylaxis were included; pediatric and pregnant patients were excluded.ResultsPre-group included 9,830 patients, post-group 10,025 patients. In both groups, the mean age was 58 years, mean weight 87 kg, and 8% of patients weighed ≥120 kg. Approximately 21% of patients were seen at the academic medical center, 8% at ambulatory surgery centers, and the remainder amongst 10 community hospitals. Most common surgical procedure types were orthopedic (26%), general surgery (21%) and urologic (10%). Primary cefazolin dose was 2 g in 89.8% vs. 88.7%, followed by 3 g 6.6% vs. 6.9% and 1 g in 3.9% vs. 4.4%, pre- and post-intervention, respectively. Overall adherence to weight-based cefazolin dosing was 92.2% pre-group and 92.4% post-group. In patients weighing ≥120 kg, adherence improved from 62% (514/827) to 71% (582/817) post-intervention, P < 0.001. Adherence was better both pre- and post-intervention when an order set was used (pre: order set 95.0% vs. no order set 85.9%, P < 0.001; post: order set 96.4% vs. no order set 84.8%, P < 0.001). There were no differences between surgical services or hospital locations. Investigation of guideline nonadherent cases found order sets without updated dosing recommendations and allowed for targeted education efforts.ConclusionOverall adherence to cefazolin weight-based dosing recommendations for surgical prophylaxis was high, especially with the use of order sets. Pharmacist-driven dose optimization intervention improved guideline adherence in patients weighing ≥120 kg.Disclosures All authors: No reported disclosures.