To define mild, moderate and severe symptom categories of the neurogenic bladder symptom score (NBSS) and NBSS-short form (SF), and to calculate the minimal clinically important difference (MCID) of the NBSS-SF.
We used existing datasets from the original NBSS validation study (n = 230 patients with spinal cord injury (SCI), multiple sclerosis, and spina bifida), and a large cross-sectional study of people with SCI (n = 1479) who completed the NBSS. We used the previously validated mild-moderate-severe categories of the ICIQ-UI, IPSS, and the SCI-QOL Bladder complications scale to define patients with mild, moderate or severe symptoms, and mapped these to the NBSS scores for the related NBSS domains of incontinence, storage/voiding, and consequences, respectively. We validated these NBSS score categories using four data sets, and by examining the global bladder problem rating. An anchor-based MCID of the NBSS-SF was determined.
Using the median/interquartile range of the associated NBSS domain score of people who were in the moderate category of the ICIQ-UI, IPSS, and the SCI-QOL Bladder complications, we calculated the severity categories for the NBSS total score: 0-32 (mild), 33-48 (moderate), and 49-74 (severe). These score categories produced significantly different NBSS scores in 29/32 comparisons in four different study populations. The global bladder problem had good agreement with each domain's categorical scale. Finally, the group-level MCID of the NBSS-SF total score was calculated as an improvement of 1.8.
We have determined interpretability ranges for the NBSS and NBSS-SF. This can help interpret patient and clinical study results.
Neurourology and urodynamics. 2026 Jun 12 [Epub ahead of print]
Jeremy Dai, Erica Li, Rose Khavari, Jorge Moreno-Palacios, Cristiano M Gomes, Jeremy Myers, John T Stoffel, Sean Elliott, Sara M Lenherr, Blayne Welk
Western University, London, Ontario, Canada., Department of Surgery, Western University, London, Ontario, Canada., Department of Urology, Houston Methodist Hospital, Houston, Texas, USA., División de Investigación, UMAE Hospital de Especialidades CMN SXXI, IMSS, Mexico City, Mexico., University of Sao Paulo School of Medicine, Sao Paulo, Brazil., Department of Surgery (Urology), University of Utah, Salt Lake City, Utah, USA., Department of Urology, University of Michigan, Ann Arbor, Michigan, USA., Department of Urology, University of Minnesota, Minneapolis, Minnesota, USA.