Neurogenic bowel dysfunction (NBD) translation and linguistic validation to classical Arabic

25 septembre 2016

Auteurs : A. Mallek, M.H. Elleuch, S. Ghroubi
Référence : Prog Urol, 2016, 10, 26, 553-557



Colorectal disorders are common in neurological diseases [1]. Several studies have been concerned with the evaluation of these disorders and their impact on the psychological condition [2] and the quality of life [3]. Among these evaluation means, different scores were used for the evaluation of constipation [4, 5] or incontinence [6, 7] though a large proportion of patients are suffering from the neurological combination of these two problems. However, none of these means of evaluation are currently available in Arabic language.

The development of objective tool evaluation is an absolute necessity face to difficulties of quantifying symptoms.

Two options for developing a scale: either translate an already existing scale or develop and validate a new scale. The first one has the advantage of allowing comparison between studies in different countries.

In this context, Krogh et al. [8] developed a standardized scale for the analysis of constipation and faecal incontinence in spinal cord injury (SCI) patients: the Neurogenic Bowel Dysfunction Score (NBD). This NBD score was used to assess symptoms as well as the effectiveness of neurogenic bowel management in individuals living with a spinal cord injury for at least ten years [9, 10].

NBD has been translated in to several languages (Danish, German, Italian, Swedish...). This work aimed at translating and linguistically validating the NBD score to classical Arabic and closed to our dialect from its French version.

Patients and methods

The index: the Neurogenic Bowel Dysfunction (NBD) score

Neurogenic Bowel Dysfunction (NBD) score is a score developed by a Danish team to assess the neurological dysfunction intestine and to identify changes in the state of the patient under treatment [8]. It includes ten items.

Total score is from 0 to 47. The higher score is, the more important the gene is:

from 0 to 6: very minor dysfunction;
from 7 to 9: minor dysfunction;
from 10 to 13: moderate dysfunction;
over14: severe dysfunction.


The translation to Arabic was conducted according to the "forward translation/backward translation" method [11, 12] and was carried out independently by three bilingual translators. These translators did not know the NBD and did not use it in their daily practices. The instruction given to each translator was to try to preserve the meaning of questions and avoid verbatim translations. The intermediate and definite versions were submitted to an expert's committee made of three doctors of physical medicine and rehabilitation to bring the necessary adaptations on a linguistic and cultural level.

The synthesis of various translations has resulted in a final Arabic version very close to the original written in a simple literary language. The final version was re-translated from Arabic into French by two other translators who were uninformed about the sought properties of the instrument. These translations were confronted with the original version.

Translation difficulties, cultural differences, conceptual equivalence and language differences have been well detected by this methodology.

Study of the series


The NBD validation was conducted with a sample of 23 patients (one patient was Egyptian, one other was Moroccan and the rest were Tunisians). They had colorectal dysfunction secondary to pathologies of the central nervous system.

The main inclusion criteria were:

adults aged from 20 to 60years in both sexes;
patients referred to our consultation, recruited for in February and March 2015;
patients with spinal cord injuries (traumatic or non-traumatic origin), outside the spinal shock phase;
patients with multiple sclerosis in remission.

The main exclusion criteria were:

cognitive and psychiatric disorders;
poor knowledge of the Arabic language;
the alteration of the intestinal or colorectal continuity: Ostomy.


We evaluated the comprehension of each item by: not understandable; doubt in understanding; understandable.

The feasibility and acceptability of our scale were studied by the number of missing answers and also by the comprehension and the time required to respond to the scale.

Patients were asked to respond to a questionnaire twice within a 15-day interval.

At T1: at the first meeting, we collected demographic data and clinical patient data. NBD was filled by the patient without assistance, and an oral interview by the same investigator was done to note the level of understanding and acceptance for each item.

At T2: after fifteen days, this self-questionnaire was administered a second time to patients who considered themselves clinically stable. The choice of this interval was based on the need for a stable clinical status on the one hand and patients not memorizing the answers on the other hand.

Statistical analysis

We used the SPSS software for Windows (version 20) to conduct the statistical analysis with a significant threshold set at P <0.05. The sociodemographic characteristics of the patients were described with averages and standard deviations.

Consistency and test-retest reliability were analyzed respectively with:

Cranach's alpha: evaluates the content validity (internal consistency);
the non-parametric correlation coefficient of spearman was used to study the Fidelity test-retest.



The "forward translation/backward translation" method led to linguistic adaptations, focusing on promoting the meaning of the item rather than achieving a literal translation. The translation difficulties were mainly due to the need to translate in to an easy literary Arabic close to the Tunisian dialect.

The synthesis of the three translators versions has resulted in a unique translation. The two-backward translations of this version were comparable to the original scale. The Committee of three doctors had agreed with the final version scale.

Validation of the Arabic translation of the score NBD

Demographic and clinical data of patients

This self-questionnaire was administered to 23 middle-aged patients 40.79±9.16years, with a sex-ratio reaching 1.85 and having colorectal disorders secondary to a neurological pathology.

Table 1 summarized the clinical and patient demographics characters.

Metrological properties of the items, feasibility

We have noticed that all the answers of item number 4 were "the irregular use of tablets against constipation" excluding two patients.

All items were considered understandable except:

for item 6: there was a doubt to understanding with 7 patients and not understandable with 2 patients;
for item 7: there was a doubt to understanding with 4 patients

These two items were not understandable because the two words "stool" and "anus" were used in French for the majority of the Tunisian population, against the Egyptian patient who reported that all was well understood.

For the item 8: 3 patients had a doubt to understanding since classical Arabic translation leaded to confusion. Therefore, its meaning has been added in brackets to facilitate understanding.

No items were excluded from the final Arabic version. The average time required to complete was 4.05±1.92minutes. There were missing responses in 1.7% of patients and no double answers.

Psychometric properties

The NBD self-administered questionnaire was filled twice with a fifteen-day interval by 23 patients. At T1, the average total NBD score was 9.47±4.9 and 9.58±5.9 at T2. The Spearman correlation shows good repeatability with 0.842.

The internal consistency of this self-administered questionnaire was considered as good through the Cronbach alpha coefficient, which reached 0.896.


In our study, we found that the NBD score Arabic version has had reproducibility and its construct validity was satisfactory.

Without a consensus about the translation methodology [13], we have adopted the "forward translation/backward translation" made by three independent translators.

We have chosen to translate to a simple literary language because literary Arabic remains the link between the various dialects in Tunisia and in other Arab countries.

The literary translation of some terms was different from the term used in the local dialect. In this case, the synonym used in the dialect can be added while these dialectical synonyms may differ from one Arab country to another or from one region to another in the same country. We have exceeded this problem with an explanation of the two words "stool" and "anus" when the questionnaire was first filled.

The repeatability of the responses to this questionnaire was good. This can hardly be explained by the small time interval between the administration of the two questionnaires, and thus to a memorization of the patients' answers. If patients could recall questions, they would hardly remember their previous answers.

We have noticed that all the answers of item number 4 were "the irregular use of tablets against constipation", except for an Egyptian patient and another one who used irregularly plant extract tablets. This is due to the fact that in Tunisia constipation treatment is available in the form of syrup or sachet and a herbal therapy product in the form of tablets that is not within the reach of all patients.

NBD score was validated for SCI patients [8] whereas in the study conducted by Fourtassi et al. [14], the effectiveness of transanals irrigation for bowel and anorectal disorders, in short- and long-term, using NBD score with a population of SCI and multiple sclerosis (MS) patients has been evaluated. In addition, in another study conducted in 2009 by Krogh and Christensen, announced that the NBD was used to evaluate the intestinal and anorectal dysfunction secondary to the impairment of the central nervous system and not applicable for patients with Parkinson's disease or myelomeningocele. In our study, we included MS and spinal cord injury patients.

The results of this study should be considered in terms of several limitations.

The sample was reduced to 23 patients compared to 258 patients in the study of Adriaansen et al. who studied the outcomes of neurogenic bowel management in individuals living with a SCI patients for at least ten years [9], which could require the continuation of this work with the recruitment of a greater number of patients to complete the validation of this scale.

We cannot use the NBD for all Tunisian SCI and MS patients because there are illiterate patients who speak only Tunisian dialect. In fact, the Tunisian people are the result of a mosaic of cultures (Arab, African, Mediterranean and French) and their dialect is very rich and varied. People who have never been to school and who know only that dialect can totally ignore the name of certain objects, verbs or even tools used in daily life in literary Arabic.

Fecal incontinence and constipation remain a taboo subject for many neurological patients. They try not to evoke their problems, not only by decency but also because their dysfunction is not important. In fact, more than half of our population has minimal and moderate dysfunction. This self-administered questionnaire allowed us to better understand the anorectal dysfunction of our patients.

The combination of vesico-sphincter disorders and anorectal dysfunction are frequently encountered due to the central neurological disease. All our patients had associated vesico-sphincter disorders. An evaluation by the USP [15], which has already undergone a translation in to Arabic, and the NBD will allow a better management of these patients and eventually improve their quality of life.


This work, never realized until now, has allowed us to obtain a reproducible Arabic version of NBD score with good outcome of construct validity despite language difficulties of the multiculturalism of target population.

The simplicity of this index allowed its use in daily clinical practice and for scientific studies of our Tunisian population. This article proposed a translated version of NBD and will be followed by a second work, which will suggest the study of its responsiveness to change with a larger number of patients.

Disclosure of interest

The authors declare that they have no competing interest.

Appendix A. Supplementary data

(44 Ko)
(14 Ko)

Table 1 - Clinical and demographic data for patients.
  Number (%) 
Nature of disease    
Spinal cord injury (traumatic/non-traumatic)  15 (65.3%) 
Multiple sclerosis  8 (34.7%) 
Clinical presentation    
No deficit motor  3 (13%) 
Paraparesis  18 (78.26%) 
Tetraparesia  2 (8%) 
Urinary symptom    
Clinical overactive bladder  10 (43.47%) 
Obstructive syndrome  5 (21.17%) 
The association of both syndromes  8 (34.7%) 
Colorectal disorders    
Constipation  15 (65.21%) 
Fecal incontinence  3 (13.04%) 
Occasional constipation and fecal leakage  5 (21.17%) 
Professional activity    
Workstopping  7 (30.43%) 
Training  1 (4.3%) 
Regular occupation  15 (65.21%) 


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