Home Testing of Blood Counts in Patients with Cancer

Background: Neutropenia is a dose-limiting toxicity of chemotherapy administered to patients with cancer. Neutrophil counts are usually measured using venous samples on centralised analysers. The aim of this work was to explore the feasibility and potential of home neutrophil count monitoring during chemotherapy. Methods: The prevalence of febrile neutropenia was defined in an unselected population using routine electronic health records of patients receiving chemotherapy for cancer. Patient and professional attitudes to home blood count monitoring were explored through questionnaires. Performance of the Hemocue WBC DIFF analyser in measuring capillary neutrophil counts was evaluated in the neutropenic range. Daily neutrophil counts were measured for the duration of a cycle of chemotherapy. Results: Baseline pathways were quantified in a Markov model using data from 28,919 patients receiving chemotherapy for cancer. Ten percent of all cancer site and chemotherapy combinations had a prevalence of febrile neutropenia of >10% (highest prevalence was 66.7%). The majority (86.9%) of patients surveyed would use home neutrophil count monitoring. Correlation of capillary Hemocue WBC DIFF measured neutrophil counts in the neutropenic range to venous ADVIA 2120 measured counts was r = 0.867, y = 0.95x + 0.01. The capillary neutrophil threshold <1.1 x10⁹/L performed best in identifying both patients at risk of febrile neutropenia and patients whose neutrophil count had not recovered prior to subsequent chemotherapy. The 21 daily neutrophil count profiles recorded during chemotherapy were heterogeneous. Four out of 10 patients with a neutrophil nadir <0.5 x10⁹/L were admitted with febrile neutropenia. Four out of 21 patients had insufficient neutrophil count recovery by day 21 for subsequent chemotherapy. Conclusion: Home neutrophil count monitoring during chemotherapy is feasible. Electronic health records can be utilised to quantify patient pathways. This work generated much evidence in support of adoption of home neutrophil count monitoring during chemotherapy, and informs future work defining the true potential.