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

Abstract

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 cancer-specific symptoms, the NCCN-FACT Bladder Symptom Index-18 (NFBISI-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 NFBISI-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 NFBISI-18 (alpha = 0.83). The NFBISI-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 NFBISI-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 NFBISI-18 should have greater acceptability to regulatory authorities than previously developed questionnaires.