(275) Evaluation of a Web-Based Application Monitoring Thiopurine Therapy in The Veterans Health Administration (VHA)

Publication Number: 606

Background: Thiopurine medications require routine monitoring (hematologic, hepatic, and serum creatinine labs) to ensure safe, appropriate treatment. Lack of routine monitoring can increase risk for serious, even fatal, adverse events like myelosuppression. Identifying patient cohorts (patients receiving azathioprine or mercaptopurine prescriptions), the VA Medical Center can increase monitoring to improve medication safety. VHA’s Medication Utilization Evaluation Tracker (MUET), a web-based application available to all VA medical centers, is a voluntary tool used to identify patients at potential risk of adverse events.

Objectives: To evaluate the monitoring of Veteran patients receiving azathioprine or mercaptopurine based on patients identified in the MUET.

Methods: This is a quality improvement review of MUET utilization to identify patients receiving an azathioprine or mercaptopurine prescription with recommended laboratory monitoring tests absent. Monthly interventions were evaluated by total patients identified missing at least one of these labs: WBC, ANC, Hgb, PLT, AST, ALT, Total bilirubin and Alkaline Phosphatase within 90 days prior to the prescription, or serum creatinine 365 days prior to the patient’s azathioprine or mercaptopurine prescription. Monthly patient cohorts were compared by number and type of interventions made. Intervention totals of monthly MUET cohorts from January 2020 to December 2021 were reviewed.

Results: From January 2020 to December 2021, a total of 9,440 patients received 163,993 prescriptions (30 day prescription equivalent). A total of 53,693 potential interventions were identified with the MUET application from January 2020 to December 2021 (patients may have multiple potential interventions identified as each monthly prescription is evaluated), and 12,981 interventions recorded in MUET for this time period. Interventions ‘Continue Therapy Lab Test Ordered’ (n = 4,689), ‘Continue Therapy VA Labs Were Within Normal Limits’ (n= 2,335), and ‘Continue Therapy Criteria for Use Met’ (n = 2,228) were the most reported interventions.

Conclusions: The MUET application recorded 12,981 interventions for patients that were missing a recommended laboratory monitoring test. The most common interventions recorded indicated the missing lab or labs had been ordered or there were labs available (perhaps more recent than cohort creation) that indicated the patient was monitored appropriately. The use of the MUET application as a potential risk identification tool can improve medication safety through increased monitoring of patients with missing labs at risk of a potential serious adverse event.