442. Risk Score for Vancomycin-Associated Acute Kidney Injury in Hospitalized Patients with Acute Bacterial Skin and Skin Structure Infections

Background Vancomycin (VAN) has been the standard empiric antibiotic for the treatment of hospitalized patients with acute bacterial skin and skin structure infections (ABSSSI) for decades but its use can be complicated by acute kidney injury (AKI). The substantial morbidity and mortality associated with AKI underscores the need to identify ABSSSI patients at increased risk for this complication. The objective of this study was to derive a clinical prediction model for VAN-associated AKI (VAN-AKI) in hospitalized patients with ABSSSI and at least one baseline traditional risk factor for AKI. Methods This was a multicenter, retrospective, case–control study between 2015 and 2018 conducted at seven academic medical centers in the USA. The population of interest was hospitalized adults with ABSSSI treated with VAN ≥72 h and initiated ≤24 h of admission. Cases consisted of patients who developed AKI according to the RIFLE criteria during VAN or ≤72 h of discontinuation. Patients who did not develop AKI served as controls. Independent predictors of VAN-AKI were identified through multivariable logistic regression. A risk score was derived using a weighted coefficient-based scoring system. Results A total of 284 patients (28 cases and 256 controls) were included. Independent predictors of VAN-AKI included in the score were: metastatic cancer, ICU admission at VAN initiation, alcohol abuse, ≥2 nephrotoxins, mental health disease, lower extremity ABSSSI and prior ABSSSI within 1 year. Patients with mental health disease had a variety of advanced chronic comorbidities and substance use. The median risk score in cases and controls was 9 (7, 11) and 4 (3.7) (P < 0.001), respectively. The risk score area under the receiver operator curve was 0.803 (95% CI 0.712, 0.894). The sensitivity, specificity, positive predictive value and negative predictive value of the risk score using a threshold of 5 points was 89.29% (95% CI 70.63%, 97.19%), 51.56% (42.27%, 57.81%), 16.78% (11.35%, 23.97%) and 97.78% (93.14%, 99.42%), respectively. Conclusion The risk score developed in this study provides a standardized, evidenced-based approach to identify hospitalized patients with ABSSSI at higher risk for VAN-AKI. External validation is required before widespread use. Disclosures All authors: No reported disclosures.