Symptom burden of cancer patients: validation of the German M. D. Anderson Symptom Inventory: a cross-sectional multicenter study.

CONTEXT: Cancer patients frequently suffer from various symptoms often impairing functional status and quality of life. To enable timely supportive care, these symptoms must be assessed adequately with reliable tools. OBJECTIVES: This study aimed to validate the German version of the M. D. Anderson Symptom Inventory (MDASI). METHODS: This was a multicenter, cross-sectional, observational study. At five German university hospitals, 697 cancer patients aged from 18 to 80 years undergoing active anticancer treatment were recruited to participate in the study. For the validation, reliability (Cronbach's alpha), construct validity (factor analysis), known group validity (Eastern Cooperative Oncology Group Performance Status), and convergent divergent analyses were calculated. RESULTS: Of the 980 patients who were eligible, 697 patients were included and agreed to participate in the study (71%). Reliability analysis showed good internal consistencies for the MDASI set of symptoms (Cronbach's alpha coefficient = 0.82; 95% CI = 0.78, 0.84) and for the set of interference items (Cronbach's alpha coefficient = 0.857; 95% CI = 0.484, 0.87). Factor analysis resulted in a one-factor solution (general symptoms; eigenvalue = 4.26) with a psychological (distress and sadness) and a gastrointestinal subscale (nausea and vomiting). Convergent and divergent analyses showed significant correlations between symptom burden and distress and global health-related quality of life (subscale of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 Version 3.0.). CONCLUSION: The MDASI-German version is a valid tool for measuring patient-reported symptom severity and symptom interference in German cancer patients. It is easily applicable and can be used by German clinicians and researchers for screening and monitoring purposes and the comparison of international data.