Background: Symptom occurrence has been shown to predict treatment course and survival in patients with solid tumors. Primary brain tumor (PBT) patients are unique in the occurrence of neurologic symptoms. Currently, no instrument exists that measures both neurologic and cancer-related symptoms.
Methods: Patients diagnosed with PBT participated in this study. Data was collected at one point in time and included demographic and clinical factors, and the M.D. Anderson Symptom Inventory-Brain Tumor Module (MDASI-BT). The study evaluated the reliability and validity of the MDASI-BT in primary brain tumor patients.
Results: Two hundred and one patients participated in this study. Mean symptom severity of items as well as cluster analysis was used to reduce the number of total items to 22 (13 core, 9 brain tumor items). Regression analysis showed more than half (56%) of the variability in symptom severity was explained by brain module items. The MDASI-BT measures six underlying constructs including affective, cognitive, focal neurologic deficit, constitutional, generalized symptom, and a gastrointestinal related factor. The internal consistency (reliability) of the instrument was 0.91. The MDASI-BT was sensitive to disease severity based on performance status (P<0.001), tumor recurrence (P<0.01), and mean symptom interference (P<0.001).
Conclusions: The 22 item MDASI-BT demonstrated validity and reliability in patients with PBT. This instrument can be used to identify symptom occurrence throughout the disease trajectory and to evaluate interventions designed for symptom management.