1301. Graphical Analysis of HIV Guidelines Adherence Finds System-Wide Anomalies in Diagnostic Testing

BACKGROUND: The misuse of HIV diagnostic tests can delay HIV diagnosis, contribute to HIV transmission, incur unnecessary costs, and pose legal risks. Prompted by case reports of misused HIV diagnostic tests, we developed a method to systematically evaluate HIV diagnostic testing that utilized an observational medical database, evaluated performance at different levels (e.g., system, facility, clinician), adjudicated clinical practice patterns as adherent or nonadherent to guidelines, quantified the impact of clinical practice deviations, and identified targets for intervention. METHODS: We used graph theory to assess patterns of HIV testing in a national healthcare system. We obtained all HIV screening tests, viral loads, and resistance tests performed January 1, 2015–January 31, 2019, excluding HIV-positive and deceased individuals (Figure 1). We modeled the CDC’s HIV diagnostic testing guidelines as a directed graph (Figure 2A). Each node in the graph represented a test, and the edges pointed from one test to the next in chronological order. We then graphed each patient’s HIV testing. This set of patient-level graphs was aggregated into a single graph. Finally, we compared the two graphs, the first representing the CDC’s recommended approach to HIV diagnostic testing and the second representing the observed patterns of HIV testing, to assess for clinical practice deviations. RESULTS: The HIV diagnostic testing of 1.643 million patients from 130 facilities provided 8.790 million HIV diagnostic test results for analysis (Figure 1). Significant deviations from recommended practice were found including the use of HIV resistance tests (n = 3,007) and HIV nucleic acid tests (n = 16,567) instead of the recommended HIV screen (Figure 2B). The estimated costs of nonadherent testing totaled $2.427 million in 2018 dollars. CONCLUSION: We developed a method that modeled a complex medical scenario as a directed graph. When applied to HIV diagnostic testing, we identified deviations in clinical practice from guideline recommendations. The model enabled the identification of intervention targets and prompted systemwide policy changes to reduce nonadherent orders and enhance HIV detection (Figure 3). This approach could be applied to diverse medical scenarios. [Image: see text] [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.