Abstract
OBJECTIVE: The MD Anderson Symptom Inventory for Brain Tumor (MDASI-BT) module is a widely used instrument for measuring symptom burden and interference of daily activities in brain tumor patients. This study aims to develop and validate its Japanese version (MDASI-BT-Japanese). METHODS: Following forward and backward translation of the original MDASI-BT into Japanese, understandability and feasibility were assessed by cognitive debriefing. Subsequently, patients with brain tumors were asked to fill out MDASI-BT-Japanese and European Quality of Life-5 Dimensions (EQ-5D). Feasibility, reliability and validity of MDASI-BT-Japanese were assessed. RESULTS: Cognitive debriefing confirmed overall ease of completion and good understandability. The study population composed of 140 patients with brain tumors (most commonly gliomas). The mean symptom severity score and mean interference score were 1.9 ± 1.7 and 2.8 ± 2.7, respectively. The top items included distress and drowsiness for symptom severity and general activity and work for interference. The median time required was 4 minutes (range, 0.5-30), and missing values were seen in 1%. Internal consistency was proven by excellent Cronbach's coefficient alpha (0.94 for symptom severity, 0.92 for interference). Test-retest reliability was assessed with acceptable intra-class correlation coefficient (mean, 0.76). Correlation efficient ranged between 0.7 and 0.9 for convergent validity. Known-group validity was confirmed by significantly different mean symptom severity score and mean interference score among patients with different performance status. As evidence of concurrent validity, MDASI-BT-Japanese correlated with EQ-5D in the hypothesized magnitude and direction. CONCLUSIONS: The newly developed MDASI-BT-Japanese has demonstrated feasibility, reliability and validity in evaluation of clinical benefit in Japanese-speaking brain tumor patients.