Validation of the M. D. Anderson symptom inventory (MDASI-BT)

Abstract

1546 Background: The occurrence of symptoms has been shown to predict treatment course and survival in a number of solid tumor patients. Primary brain tumor patients are unique in the neurologic symptoms that occur. Currently, no instrument exists that measures both neurologic and cancer-related symptoms. Methods: Patients diagnosed with Primary Brain Tumors (PBT) participated in this study. Data collection tools included a patient completed demographic data sheet, an investigator completed clinician checklist, and the core M.D. Anderson Symptom Inventory to which 18 neurologic symptoms were added (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: 201 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. Regression analysis showed more than half (56%) of the variability in symptom severity was explained by the 9 remaining brain tumor items. Factor analysis was then performed to determine the underlying constructs being evaluated by the remaining items. The 22 item 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 sets of items comprising the six factors and also the interference scale were .87, .82, .72, .81, .69, .67 and .91 respectively). Test-retest reliability was good in a subset of 19 patients completing the instrument at two points in time. The MDASI-BT was sensitive to disease severity based on Karnofsky performance status (KPS) based on mean symptom severity (1.7 versus 3.8, p < .001) and mean symptom interference (2.2 versus 6.1, p < .001). Conclusions: The 22 item MDASI-BT demonstrated validity and reliability in patients with PBT. This instrument can be used to describe symptom occurrence throughout the disease trajectory and to evaluate interventions designed for symptom management. [Table: see text]