Psychometric validity and reliability of the Danish version of the MD Anderson Symptom Inventory Brain Tumor Module

Background: The complexity of disease- and treatment-related symptoms causes profound distress and deterioration of health-related quality of life among patients with brain tumors. Currently, there is no Danish validated disease-specific instrument that focuses solely on measures of both neurologic and cancer-related symptoms of patients with brain tumors. The MD Anderson Symptom Inventory Brain Tumor Module (MDASI-BT) is a validated patient self-report questionnaire that measures symptom prevalence, intensity, and interference with daily life. The aim of the present study was to determine the psychometric validity of the Danish translation of the MDASI-BT, and to test its utility in 3 cohorts of Danish patients across the spectrum of the brain cancer disease and treatment trajectory. Methods: A linguistic validation process was conducted. Danish patients with malignant primary brain tumors were included to establish the psychometric validity and reliability of the Danish MDASI-BT. Cognitive debriefing interviews were conducted to support the psychometric properties. Results: A total of 120 patients participated in this study. Coefficient αs for the symptom and interference subscales indicate a high level of reliability across all items. Corresponding symptom and interference or functional items and subscales in the MDASI-BT and European Organisation for Research and Treatment of Cancer Brain Tumor Module BN20 were significantly correlated. Cognitive debriefing provided evidence for content validity and questionnaire utility as participants were comfortable answering the questions and had no problem with the understandability or number of questions asked. Conclusion: The MDASI-BT is a simple, concise symptom assessment tool useful for assessing the symptom severity and interference of Danish-speaking patients with brain cancer.