Reliability and Validity of the Neurogenic Bladder Symptom Score in Adults with Cerebral Palsy

Objective: To examine the utility of the Neurogenic Bladder Symptom Score (NBSS) in adults with cerebral palsy (CP). Methods: Patients participated in a structured intake which included bladder management. Patients (or caregivers, if patients unable) completed NBSS and SF-Qualiveen twice over a 2-week period. Validity was determined using Cronbach's alpha and correlation testing between NBSS, intake, and SF-Qualiveen. Reliability was determined using test-retest method and intraclass correlation coefficients. Results: Fifty-four patients were included. Thirty-six patients (67%) used a wheelchair; 35 patients (66%) required a caregiver to complete questionnaires. Median NBSS subdomain scores were 12 of 29 for incontinence, 9 of 22 for storage and/or voiding, 2 of 23 for consequences and 1 of 4 for quality of life (QOL). Lower scores reflect fewer symptoms. Reliability was high (intraclass correlation coefficients = 0.90). There was a moderate correlation (R = 0.70) between NBSS QOL and SF-Qualiveen. Bladder management method, as determined by the NBSS, was indwelling catheter in 4, intermittent catheterization in 6, voiding into a toilet in 33, and missing in 11. Importantly, there was no option for voiding into a diaper, which was common in this population. Conclusion: For adults with CP, the NBSS has high reliability and statistically, it demonstrated appropriate validity, but it has limitations. Its face validity is questionable given that diapers were not an option. The validity of caregiver completion needs further assessment. The NBSS may have a floor effect for detecting urinary consequences or QOL, reflected by consistently low scores in these subdomains. The development of a specific urinary symptom and/or QOL tool for adults with CP is needed.