The Bladder Utility Symptom Scale: A Novel Patient Reported Outcome Instrument for Bladder Cancer

Abstract

Health related quality of life is important in bladder cancer care and clinical decision making because patients must choose between diverse treatment modalities with unique morbidities. A patient reported outcome measure of overall health related quality of life for bladder cancer regardless of disease severity and treatment could benefit clinical care and research. Prospective questionnaire development was completed in 3 parts. In study 1 the BUSS (Bladder Utility Symptom Scale) questions were created by experts using a conceptual framework of bladder cancer health related quality of life generated through patient focus groups. In study 2 patients with bladder cancer, including those treated with surgery, radiation and chemotherapy, completed the BUSS and 5 health related quality of life instruments at baseline and 4 weeks to assess validity and test-retest reliability. External validity was then explored in study 3 by administering the BUSS to 578 patients online and at clinics. Construct validity was assessed by whole and subscale Spearman rank correlations, and by comparisons of BUSS scores across known groups. The BUSS had high whole scale correlation with the FACT-Bl (Functional Assessment of Cancer Therapy-Bladder) (rs = 0.82, p <0.0001) and substantial to high subscale correlations with the EQ-5D™-3L (EuroQol 5 Dimensions Questionnaire-3 Levels) (eg emotional well-being rs = 0.69, p<0.0001). BUSS scores were lower in patients with comorbidity and advanced disease. Cognitive debriefing and the 94% completion rate suggested good comprehensibility. There was excellent test-retest reliability (ICC = 0.79). Limitations included an extended time from diagnosis in many patients. The BUSS is a reliable and valid patient reported outcome instrument for health related quality of life in all patients with bladder cancer regardless of the treatment received or the stage of disease.