1608. Use of Selective Reporting of Antimicrobial Susceptibilities and Its Impact on Antimicrobial Resistance Surveillance—National Healthcare Safety Network, 2017–2018

BACKGROUND: Selective reporting (SR), recommended by the 2016 IDSA/SHEA antimicrobial stewardship guidelines, is a strategy to guide prescribing decisions by limiting the antimicrobial susceptibility testing (AST) results available to prescribers. Yet, SR carries risks that cumulative antibiograms reflect only partial AST results. The Clinical Laboratory Standards Institute (CLSI) M100 performance standards stipulate that AST results should be routinely reported for some antimicrobials (Group A agents) while SR is appropriate for other antimicrobials (Group B agents). We assessed the extent of SR use and its impact on national antimicrobial resistance (AR) surveillance. METHODS: We used Enterobacteriaceae (EB) and Staphylococcus aureus (SA) blood culture AST results that hospitals reported for group A and B agents to the CDC’s National Healthcare Safety Network’s AR option from 2017 through 2018. Routine reporting for an organism-agent combination was defined as results reported for ≥ 90% isolates for the hospital’s most frequently reported agents. SR was defined as a shortfall of > 20% in results reported for an agent compared with a routinely reported agent in a hospital that reported ≥ 30 isolates. We compared hospital antibiograms between SR and non-SR hospitals. We also identified isolate characteristics associated with AST reporting in SR hospitals. RESULTS: Among 242 and 185 hospitals reported ≥ 30 isolates, many showed patterns of SR (Figure 1). Of 437 and 425 hospitals reported ≥ 1 isolate, only 112 (26%) and 152 (36%) routinely reported AST results for all group A agents for EB and SA, respectively. For EB, 345 (79%) hospitals routinely reported AST results for ciprofloxacin or levofloxacin, although both are group B agents. For SA, 324 (76%) routinely reported vancomycin (Figure 2). Antibiograms for many agents differed between SR and non-SR hospitals (Figure 3, 4). In SR hospitals, non-susceptibility to narrower-spectrum drugs, patient location, age, and some species among EB were associated with AST reporting. CONCLUSION: AST results reporting vary across hospitals and agents, and CLSI’s SR standards are used inconsistently. For AR surveillance, complete reporting calls for solutions that bypass SR. In the meantime, SR should be taken into account in national AR benchmarking. [Image: see text] [Image: see text] [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.