The Neurogenic Bladder Symptom Score (NBSS): a secondary assessment of its validity, reliability among people with a spinal cord injury.

STUDY

DESIGN

Prospective cross-sectional study.

OBJECTIVES

Validate the Neurogenic Bladder Symptom Score (NBSS) for people with spinal cord injury (SCI).

SETTING

United States (recruitment from community/tertiary neurourology clinics).

METHODS

We used data from a prospective observational study of people with a SCI who enrolled during December 2015-September 2016. Participants completed the NBSS and other measurement tools (SF-12 and SCI-QOL Bladder Management Complications tool). Data were used to determine the internal consistency (Cronbach's alpha), validity (hypothesis testing), and test-re-test reliability (using an intraclass correlation coefficient).

RESULTS

609 people with a SCI had complete data. The median NBSS total score was 22 (IQR 15-30), and median quality of life was "mixed". The Cronbach's alpha of the total and the incontinence, storage/voiding, and consequences domains was 0.85, 0.93, 0.76, and 0.49 respectively. All item to domain correlations were ≥0.3, aside from 3/7 of the items from the consequences domain. Appropriate correlations between the NBSS domains and external variables and other questionnaires were observed, such as a moderate correlation between the SCI-QOL Bladder Management complications tool and the NBSS total score. For the reliability assessment, 174 people had 3 month followup data and did not have a significant change to their urologic health. The intraclass correlation coefficients were >0.75 for all subdomains and the overall score.

CONCLUSIONS

The NBSS demonstrated good validity and reliability in a large cohort of people with a SCI, and is a suitable tool to assess neurogenic bladder symptoms.

SPONSORSHIP: Patient-Centered Outcomes Research Institute (PCORI) Award CER14092138.