Real-World Accuracy of Continuous Glucose Monitoring During Intensive Hematological Care: A Prospective Study

Background: Patients treated for a hematological malignancy are susceptible to hyperglycemia, which can negatively affect treatment outcomes. Therefore, close monitoring of glucose levels is crucial. Data demonstrated that capillary measurement methods underreport hyperglycemic episodes compared with continuous glucose monitoring (CGM). However, the accuracy of CGM during intensive hematological treatments, and the associated metabolic and hemostatic imbalances, is unknown, which we aim to investigate in the current study. Methods: For the analysis, data collected during a prospective study that compared CGM with capillary point-of-care (POC) glucose measurements in adult patients hospitalized for intensive hematological care with three different treatment modalities, namely chimeric antigen receptor T-cell therapy, allogeneic stem cell transplantation (allo-SCT), or autologous stem cell transplantation (auto-SCT), were used. POC and CGM measurements were performed concurrently. Accuracy was assessed using mean and median absolute relative difference (MARD), Diabetes Technology Society (DTS) Error Grid analysis as well as percentages of values within 15%/15, 20%/20, and 30%/30 mg/dL. Results: A total of 60 patients (28% female, median age 64 [58-68] years and 10% with a history of diabetes mellitus) were included, yielding 1999 matched measurement pairs. The overall mean ARD was 21.5%, whereby the lowest mean ARD was observed during allo-SCT (18.3%) and the highest mean ARD during auto-SCT (27.1%). The percentages of glucose values within 15%/15, 20%/20, and 30%/30 mg/dL agreements were 38.1%, 51.1%, and 75.1%. The DTS Error Grid analysis showed good clinical accuracy with 99.6% of pairs within zone A + B. Conclusions: Despite the relative high MARD, the use of CGM is unlikely to result in harmful insulin dosing errors and seems feasible to use during intensive hematological care.