Neurogenic dysfunction of the lower urinary tract is one of the most challenging problems in urology. From time immemorial, several questionnaires have been designed to assess patients' urinary symptoms, most of which fall into two groups: The first group includes questionnaires that assess the quality of life of neurological patients, such as the SCI Specified Qol Scale. The second category includes symptom-based questionnaires. Most of these questionnaires are designed for women only and some of them are designed for men and a very small number are designed for specific urinary symptoms such as incontinence or urinary urgency (2). Therefore, the urgent need for a suitable questionnaire to assess urinary symptoms in a wide range of neurological patients was strongly felt. Welk et al. designed the NBSS (Neurogenic Bladder Symptom Score) questionnaire in 2013; a conceptual questionnaire that assessed lower urinary tract symptoms in men and women with congenital or acquired neurological disorders (1-3). The current study aimed to translate the Neurogenic Bladder Symptom Score (NBSS) questionnaire considering linguistic and cultural differences and evaluate the validity and reliability of the Persian version.

Translation and back-translation process: 
After obtaining permission from Welk et al., two Persian native speaker urologists translated the questionnaire separately. The final Persian version was back-translated into English by two professional translators, who were not medical staff and were not familiar with the NBSS. Following an agreement with Welk et al, the Persian version was checked by ten expert urologists for simplicity, comprehensibility, and accuracy of the content. 
Validation of the Persian version of the NBSS: 
First, a urologist interviewed virtually 10 participants (MS, or stroke) who completed the final Persian version of NBSS, to assess their comments on the content, clarity, and simplicity of the questionnaire parameters. Then patients over 18 years of age with multiple sclerosis or stroke with a neurogenic bladder filled out the questionnaire. 
Validity:
 Content and face validity were assessed considering expert opinions. Both quantitative and qualitative methods were used to determine the content validity.
Internal consistency :
Internal consistency was assessed using Cronbach’s alpha. Values between 0.70 and 0.90 were considered to be acceptable. Reliability :
To determine the NBSS reliability, we assessed the test-retest reliability results completed by participants within a 15 days interval. Statistical analysis 
First, all data were inputted into EXCEL (2013) and then analyzed using IBM SPSS 24.0 software. The data normality was evaluated using descriptive evidence.

In the current study 186 MS patients, and 93 patients with stroke, completed the questionnaire. Most of the participants were female (73.1%). The mean (SD) age was 45.8 (17. 6) years (minimum 19, maximum 90). For question 24, which evaluates the impact of NGB on QoL, the median score was 2 [1-4], indicating a predominance of patients dissatisfied with the QoL about their bladder condition. The median total score was 15 [4 to 51]. The median for the incontinence subdomain was 1 [0-29], for storage and voiding were 11 [1-18], and for the consequences subdomain, was 2 [0-12]. 
Validity:
For face validity, we interviewed 10 participants with different ages (range: 32–70 years old) and occupations (housewife, teacher, nurse, student, or physician) who had completed the NBSS questionnaire. Most of them found the NBSS is easy to complete. 
Internal consistency 
Our results showed a Cronbach alpha of 0.85. Cronbach alpha coefficient was 0.96 for the incontinence subdomain, 0.78 for storage and voiding, and 0.73 for the consequences subdomain. All of the parameters achieved a score greater than 0.7, indicating good internal consistency.
Reliability 
The test-retest reliability was assessed by intra-class correlation coefficients (ICCs) for each subdomain (Table 1). The ICCs were high for all subdomains, indicating good agreement between the first and second tests.
In our evaluation, the I-CVI for all subdomains of the NBSS value was 1 and the majority of items were considered relevant. In terms of CVR, all criteria gained a high score, and all experts believed that all criteria of the NBSS were essential for patient evaluation (Table 2).

Due to the fact that urological problems are common in these patients, the need to use a valid questionnaire is felt. Considering linguistic and cultural differences, the Persian version NBSS questionnaire is a valid and reliable tool to assess neurogenic bladder for clinical and research purposes.

Considering linguistic and cultural differences, the Persian version NBSS questionnaire is a valid and reliable tool to assess neurogenic bladder for clinical and research purposes.

Welk B, Morrow S, Madarasz W, Baverstock R, Macnab J, Sequeira K. The validity and reliability of the neurogenic bladder symptom score. The Journal of urology. 2014;192(2):452-7.
Welk B, Morrow SA, Madarasz W, Potter P, Sequeira K. The conceptualization and development of a patient-reported neurogenic bladder symptom score. Research and reports in urology. 2013;5:129.
Guler MA, Dogan D, Yilmaz Yalcinkaya E. Validity and reliability of the Turkish version of the neurogenic bladder symptom score. Disability and Rehabilitation. 2020:1-7.