Measuring priority symptoms in advanced bladder cancer: Development and initial validation of a brief symptom index

Background: Improved measurement of clinically meaningful symptoms is needed in advanced bladder cancer. Objective: This study developed and examined the initial reliability and validity of a new measure of advanced bladder cancerspecific symptoms, the NCCN-FACT Bladder Symptom Index-18 (NFBlSI-18), which assesses the symptoms perceived as most important by patients and oncology clinical experts. Methods: A total of 31 individuals with advanced bladder cancer rated the importance of 28 symptoms. In addition, 10 oncology clinical experts rated symptoms as treatment- or disease-related. Patient-rated symptoms were reconciled with published clinicians' symptom priorities, producing the NFBlSI-18. Participants completed measures of quality of life (QOL) and performance status to examine initial validity. Results: An 18-item symptom index for advanced bladder cancer included 3 subscales: disease-related symptoms, treatment side effects, and general function/well-being. Lower scores indicate greater symptom burden. Preliminary reliability reveals good internal consistency for the full NFBlSI-18 (α = 0.83). The NFBlSI-18 was significantly associated with QOL criteria and performance status, in the expected direction. Limitations: Limitations include the cross-sectional design and the relatively low reliability of the disease-related symptoms subscale. Conclusion: The NFBlSI-18 demonstrates preliminary evidence as a valid brief measure of the most important symptoms of advanced bladder cancer, as rated by both patients and oncology clinical experts. The NFBlSI-18 should have greater acceptability to regulatory authorities than previously developed questionnaires.