The creation and validation of a short form of the Neurogenic Bladder Symptom Score

Abstract

Aim To develop a short form (SF) of the 24-item Neurogenic Bladder Symptom Score (NBSS). Methods We used three previously published datasets. First, we selected the most responsive questions within each of the domains. Internal validity of the NBSS-SF was assessed using Cronbach's alpha. External validity was assessed by evaluating hypothesized relationships with other questionnaires and testing correlations with the full NBSS domains. Test-retest reliability of the NBSS-SF domains was determined using an intraclass coefficient (ICC). Results Using data from a prior responsiveness study, we selected questions for the NBSS-SF from the incontinence domain (three), storage/voiding domain (three), consequences domain (two); these would make up the NBSS-SF. We used the original NBSS validation cohort of 230 patients with multiple sclerosis (MS), spinal cord injury (SCI), or spina bifida, and found the Cronbach's alpha was .76 for the NBSS-SF; the external validity was high, with correlations between specific NBSS-SF domains/total scores and the Qualiveen-SF, ICIQ, and AUASS generally similar to those seen with the NBSS. Correlations between the NBSS-SF domains and the full NBSS domains were high. The NBSS-SF ICC in a subset of 120 patients was 0.84. The NBSS-SF performed similarly in two additional independent datasets. Conclusions The total score of the NBSS-SF has appropriate validity, reliability, and could be used instead of the full NBSS to minimize the assessment burden. The full NBSS may be better suited if the primary focus of the study is on neurogenic bladder symptoms, or if individual NBSS domains are of interest.