Reliability and validity of Turkish version of neurogenic bowel dysfunction score in patients with spinal cord injury

Objective: Neurogenic Bowel Dysfunction (NBD) score assess the severity of clinical symptoms of neurogenic bowel dysfunction in patients with spinal cord injury. The aim of this study is to investigate the validity, reliability and sensitivity to change of the Turkish version of NBD score. Materials and Methods: Translation, back translation and cross cultural adaptation of the NBD score into Turkish was done according to the suggested guidelines. The study included forty two patients (with a mean age of 39.29 ± 15.64 years) with spinal cord injury who were admitted to the Department of Physical Medicine and Rehabilitation, Dokuz Eylül University Faculty of Medicine. Demographic variables and level of SCI according to the ASIA impairment scale were recorded. The quality of life was assessed with the SF-36 questionnaire; the impact of neurogenic bowel dysfunction on quality of life was assessed with a 5-point Likert scale. The physician global assessment was recorded on a 10 cm visual analog scale. The reliability of NBD score was assessed by test-retest reliability and internal consistency. Cronbach's alpha coefficient was calculated to determine internal consistency. We evaluated the construct validity by exploring correlations between the NBD score and SF-36 scales, the effect of neurogenic bowel dysfunction on quality of life and the physician global assessment. The patients with moderate dysfunction (NBD score 10-13) and severe dysfunction (NBD score≥14) are selected and both neurogenic bowel program and patient education were given. These patients were reassessed to investigate the sensitivity of the score to change. The Global Rating of Change (GRC) scale was used to assess the change of neurogenic bowel dysfunction. The factors associated with neurogenic bowel dysfunction were also analyzed. Results: Cronbach's alpha coefficient for internal consistency was 0.547. In test- retest relability analysis high correlations between total test-retest NBD score and answers of each question were found (r:1.000, p:0.000). The consistency of frequency distribution of all answers for each item analyzed by kappa statistics and very high consistency was found (kappa:1.000, p:0.000). Significant correlations between NBD score and Physician Global Assessment (r:0.98, p<0.000) and the impact on quality of life (r:0.92, p<0.000) were found. There was a significant negative correlation between NBD score and subscales of SF-36 except RF, RP and PCS (p<0.05). When total NBD scores before and after treatment were compared to investigate the sensitivity to change, statistically significant improvement was found at the end of two months (p: 0.011). There was also a significant positive correlation between GRC scale and change in total NBD score at the second month of treatment (r: 0:821, p: 0.007). When the correlations between NBD score and age, gender, age of injury, duration of injury, level of injury and severity of injury were assessed, NBD score was correlated only with the severity of injury (r:-0.433, p<0.004). Conclusions: The Turkish version of NBD score was found valid and reliable.