Category: Federal Forum Posters
Purpose: The rate of bone involvement in the metastatic setting is highest among breast cancer, prostate cancer, and multiple myeloma. The Food and Drug Administration approved zoledronic acid at a dose of 4mg administered intravenously every 3 to 4 weeks for this indication. However, recent studies have shown a 12-week dosing interval to be non-inferior to a 4-week dosing interval. The purpose of this study is to evaluate the use of zoledronic acid within the Veteran’s Health Administration (VHA). We will analyze dosing intervals, determine incidence of skeletal-related events and hypocalcemia, and quantify potential cost-savings of a longer dosing interval.
Methods: A retrospective review will be conducted of patients within the VHA who received zoledronic acid between April 1, 2017 and October 1, 2018 for bone involvement from breast cancer, prostate cancer, or multiple myeloma. Study data will be identified and collected from the Veteran Affairs (VA) Corporate Data Warehouse through the VA Informatics and Computing Infrastructure. All zoledronic acid treatment doses will be examined to determine each patient’s dosing interval, which will be categorized as either 4-week or 12-week. A creatinine clearance will be calculated for each patient, utilizing the Cockcroft-Gault equation, prior to each received dose to determine appropriate dosing based on prescribing information. The patients’ electronic medical records will be further examined to identify incidence of toxicity from the medication, specifically skeletal-related events and hypocalcemia, for each dosing interval. The estimated cost-savings will be quantified utilizing dosing interval data and the publicly-available contracted price of zoledronic acid at the time of data analysis. Baseline demographics will be analyzed using descriptive statistics. The primary outcome will be analyzed using a chi-squared test. Secondary outcomes will be analyzed using descriptive statistics, and further analysis may be done using a chi-squared test.
Gregory Sneed– PGY1 Community Pharmacy Resident, Nationwide Children's Hospital, Columbus, OH