Validation of the Dutch-Language Version of the Neurogenic Bowel Dysfunction Score in Patients With Multiple Sclerosis

Abstract

Neurogenic bowel dysfunction (NBD), like fecal incontinence and constipation, is a common symptom of disease in patients with multiple sclerosis (MS). The NBD score is a validated symptom-based questionnaire consisting of 10 multiple-choice questions. The aim of this study was to validate the Dutch version of the NBD score in patients with MS, creating an objective measuring tool of bowel dysfunction. Translation and validation of the NBD score was performed according to standardized guidelines. Adult patients with MS visiting a urology department completed a set of questionnaires (test): the NBD score, the Fecal Incontinence Quality of Life scale (FIQL), the Fecal Incontinence Severity Index (FISI), and the EQ-5D 3-Level questionnaire (EQ-5D-3L). After 1 to 2 weeks, the questionnaires were completed again (retest). A control group recruited at a general practitioner's practice completed the questionnaires once. Data were analyzed for measurement properties. Sixty-one patients and 50 controls were included. Content validity was adequate, internal consistency was moderate (Cronbach α = 0.57 and 0.41), and reproducibility was excellent (interclass correlation coefficient = 0.78). Criterion validity was confirmed; the NBD score correlated moderately/strongly with the FIQL, FISI, and EQ-5D-3L. The NBD scores in the patient group were significantly higher than those in the control group, demonstrating good construct validity. The Dutch version of the NBD score showed moderate to good validity and good reliability for assessment of NBD in patients with MS.