B-298 Impact of In-House Methotrexate Serum Testing on Clinical Management and Patient Discharge in Acute Lymphoblastic Leukemia

Le résumé fourni par la source

Abstract Background Methotrexate (MTX) is a critical chemotherapeutic agent for leukemia, particularly acute lymphoblastic leukemia (ALL), and for central nervous system prophylaxis. Due to its narrow therapeutic index and the risk of toxicity, therapeutic drug monitoring is essential. Previously, MTX serum testing was sent to reference laboratories, which did not meet clinical practice needs. On March 9, 2023, in-house MTX testing was implemented. This study compares the performance of in-house testing with send-out testing and evaluates its impact on clinical management for ALL patients. Methods A retrospective chart review analyzed MTX serum tests for inpatient ALL patients from January 1, 2020, to December 31, 2024, covering 38 months of send-out testing (January 1, 2020–March 8, 2023) and 22 months of in-house testing. The initial dataset included all patients, but those with major complications or comorbidities (MCC), identified via Diagnosis-Related Group (DRG) coding, were excluded from discharge pattern analysis to reduce confounding factors. Results Among 1,299 MTX tests (773 adults, 526 pediatric cases), 936 were send-out tests, and 363 were in-house tests. Of the 738 cases without MCC, 457 were adults (379 send-out, 78 in-house) and 281 were pediatric (187 send-out, 94 in-house). Discharge times for send-out cases peaked at 7 a.m. and 10-11 a.m., suggesting delays due to overnight test results. In contrast, in-house testing led to more evenly distributed discharges in the morning and early afternoon. The last MTX result before discharge peaked between 3–6 p.m. for send-out tests, while in-house results were delivered at least two hours earlier (1–3 p.m.), enabling earlier clinical decisions (Fig 1). Conclusion In-house MTX testing improved turnaround times, facilitating earlier patient discharge and reducing overnight stays. This enhanced clinical efficiency and resource utilization, ultimately benefiting ALL patient care.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.