|Year : 2015 | Volume
| Issue : 3 | Page : 303-308
Hindi translation and validation of Cambridge-Hopkins Diagnostic Questionnaire for RLS (CHRLSq)
Ravi Gupta1, Richard P Allan2, Ashwini Pundeer1, Sourav Das1, Mohan Dhyani1, Deepak Goel3
1 Department of Psychiatry and Sleep Clinic, Himalayan Institute of Medical Sciences, Swami Ram Nagar, Doiwala, Dehradun, Uttarakhand, India
2 Department of Neurology, Johns Hopkins University, Baltimore, Maryland, United State
3 Department of Neurology and Sleep Clinic, Himalayan Institute of Medical Sciences, Swami Ram Nagar, Doiwala, Dehradun, Uttarakhand, India
|Date of Submission||04-Dec-2014|
|Date of Decision||25-Dec-2014|
|Date of Acceptance||02-Feb-2015|
|Date of Web Publication||6-Aug-2015|
Department of Psychiatry and Sleep Clinic, Himalayan Institute of Medical Sciences, Swami Ram Nagar, Doiwala, Dehradun - 248 140, Uttarakhand
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Restless legs syndrome also known as Willis-Ekbom's Disease (RLS/WED) is a common illness. Cambridge-Hopkins diagnostic questionnaire for RLS (CHRLSq) is a good diagnostic tool and can be used in the epidemiological studies. However, its Hindi version is not available. Thus, this study was conducted to translate and validate it in the Hindi speaking population. Materials and Methods: After obtaining the permission from the author of the CHRLSq, it was translated into Hindi language by two independent translators. After a series of forward and back translations, the finalized Hindi version was administered to two groups by one of the authors, who were blinded to the clinical diagnosis. First group consisted of RLS/WED patients, where diagnosis was made upon face to face interview and the other group - the control group included subjects with somatic symptoms disorders or exertional myalgia or chronic insomnia. Each group had 30 subjects. Diagnosis made on CHRLSq was compared with the clinical diagnosis. Statistical Analysis: Analysis was done using Statistical Package for Social Sciences (SPSS) v 21.0. Descriptive statistics was calculated. Proportions were compared using chi-square test; whereas, categorical variables were compared using independent sample t-test. Sensitivity, specificity, and positive predictive value of the translated version of questionnaire were calculated. Results: Average age was comparable between the cases and control group (RLS/WED = 39.1 ± 10.1 years vs 36.2 ± 11.4 years in controls; P = 0.29). Women outnumbered men in the RLS/WED group (87% in RLS/WED group vs 57% among controls; χ2 = 6.64; P = 0.01). Both the sensitivity and specificity of the translated version was 83.3%. It had the positive predictive value of 86.6%. Conclusion: Hindi version of CHRLSq has positive predictive value of 87% and it can be used to diagnose RLS in Hindi speaking population.
Keywords: CHRLSq, restless legs syndrome, translation, validation, Willis-Ekbom′s disease
|How to cite this article:|
Gupta R, Allan RP, Pundeer A, Das S, Dhyani M, Goel D. Hindi translation and validation of Cambridge-Hopkins Diagnostic Questionnaire for RLS (CHRLSq). Ann Indian Acad Neurol 2015;18:303-8
|How to cite this URL:|
Gupta R, Allan RP, Pundeer A, Das S, Dhyani M, Goel D. Hindi translation and validation of Cambridge-Hopkins Diagnostic Questionnaire for RLS (CHRLSq). Ann Indian Acad Neurol [serial online] 2015 [cited 2020 Jan 27];18:303-8. Available from: http://www.annalsofian.org/text.asp?2015/18/3/303/162290
| Introduction|| |
Restless legs syndrome, recently named as Willis-Ekbom's Disease (RLS/WED) is a common illness with the reported prevalence of 2-11% across different studies. ,,,,, This variation in the prevalence could be ascribed to the difference in methodologies adopted for the diagnosis of RLS/WED. Despite it being a common problem, it still remains an under diagnosed entity. , However, over diagnosis is also not uncommon and this can be related to the misidentification of conditions that mimic RLS/WED. 
The Cambridge-Hopkins RLS diagnostic questionnaire (CHRLSq) was developed to make a reliable diagnosis of RLS/WED during surveys and epidemiological studies. It contains 22 items that are completed by patient himself. It has been found to have87% sensitivity and 94% specificity along with positive predictive value of 86% in a study done in Cambridge, England.  This questionnaire seeks to exclude some conditions that mimic RLS/WEDto improve the identification of'true RLS/WED'. 
CHRLSq was originally developed in English language. However, many Indians do not have adequate knowledge of English language. This is a major issue when we try to assess the prevalence of RLS/WED in Hindi speaking region of India. Thus, we planned the present study to translate and validate the CHRLSq in Hindi. We have followed the same methodology during the process of translation and validation of this instrument, which was adopted during translation and validation of International RLS Severity Rating Scale (IRLS) and RLS related Quality of life questionnaire (RLSQoL) in Hindi. ,,,
| Materials and Methods|| |
This study was conducted in the Sleep Clinic of a tertiary care teaching hospital after obtaining permission from the principal authors of CHRLSq between April 2014 and June 2014.  All the subjects included in this study were explained the rationale of this study and were requested to participate. An informed consent was obtained from all the subjects.
All adult patients attending sleep clinic were screened for the presence of RLS/WED according to the criteria proposed by International RLS Study group by an expert.  Patients having conditions that mimicked RLS/WED were excluded; so were the patients on psychotropic medications. Patients with chronic medical illness, substance abuse, and neurological disorders were also excluded. The control group consisted of subjects with medically unexplained somatic symptoms or presenting with exertional myalgia in legs or those suffering from insomnia, but not meeting the criteria for RLS/WED on clinical evaluation. ,,
Their demographic data was recorded. It included age, gender, and years of education. Based upon the literacy status, subjects were divided into four groups: Those who had never attended the school-illiterate; those who had 1-5 years of education- primary; those with 6-12 years of education- secondary; and lastly, who completed 13 or more years of education- graduate.
Thereafter, subjects were interviewed using the Hindi version of CHRLSq by other authors who were blinded to the clinical diagnosis. Responses were noted for of the each items and diagnosis of RLS/WED was made according to the responses provided on this questionnaire.
Translation of the instrument
We have followed the guidelines for the cross-cultural translation and validation as suggested by Sousa and Rojjanasrirat. 
Firstly, CHRLSq was translated by two bilingual persons into Hindi language (version 1 and 2). Thereafter, these versions were compared for the translational inconsistencies, they were discussed among both the translators and finally a third Hindi version was obtained. This version was back translated in English by two bilingual translators independently (4 th and 5 th versions). These versions were again compared for the translational inconsistencies and after discussing the issues, 6 th common version of the CHRLSq was obtained. The 6 th version was compared with the original instrument and inconsistencies were sorted. All the four translators now worked together, discussed the inconsistencies, and thus appropriate changes were made in the 3 rd version so as to bring it closest to the original instrument. This provided us the finalized 7 th version in Hindi which was used for the validation in clinical population.
Statistical analysis was done using Statistical Package for Social Sciences (SPSS) v 21.0. Descriptive statistics was analyzed. Independent sample t-test was used to compare categorical variables between two groups and chi-square was used for the comparison of proportions. Sensitivity and specificity of the diagnosis by the questionnaire were calculated against the clinical interview. Positive predictive value was also calculated.
| Results|| |
Thirty patients of RLS/WED and 30 controls were included in this study. Average age was comparable between the cases and control group (RLS = 39.1 ± 10.1 years vs 36.2 ± 11.4 years in controls; P = 0.29). As expected, women outnumbered men in the RLS/WED group (87 vs 57% among controls; χ2 = 6.64; P = 0.01). Twenty-seven percent of RLS/WED patients and 17% of controls were illiterate; however, the level of education (primary, secondary, or graduate) was comparable between both the groups. In the control group, 23% had major depressive disorder with somatic symptoms, 30% had chronic insomnia, and 47% were suffering from somatic symptoms disorder.
Forty percent of the controls and 100% of the RLS patients replied 'yes' to the item number 1; 40% of the controls and 97% of the RLS patients replied 'yes' to item number 2. Interestingly, 37% of the controls marked 'yes' to both the items, that is, items 1 and 2; on the contrary, among RLS group, all except one subject responded 'yes' to both of these items. Gender, education level, and the diagnosis did not appear to have any effect on the responses to either of these items in the control group.
Sensitivity and specificity
The clinical diagnosis of RLS/WED is considered to be the gold standard and hence, the diagnosis made by the questionnaire was checked against it. We had four diagnostic categories from the questionnaire - definite RLS/WED, definitely not RLS/WED, probable RLS/WED, and uncertain diagnosis. In the control group, distribution of subjects was as follows: 'Definitely not RLS/WED'-17 subjects; 'definite RLS/WED' - four subjects; 'probable RLS/WED' - one subject; and 'uncertain diagnosis' - eight subjects. In the RLS/WED group, 20 subjects received the diagnosis of 'definite RLS/WED'; five subjects fell into the rubric of 'probable RLS/WED'; while five subjects were categorized as 'uncertain diagnosis'. None of the subjects in this category was diagnosed as "definitely no RLS/WED". From the clinical point of view, 'definite RLS/WED' and 'probable RLS/WED' were considered as RLS/WED while the remaining two categories as not RLS/WED [Table 1]. These results were obtained when item 6 of the questionnaire on relief with movement was controlled as in the cases of severe RLS, even the movement may not bring the complete relief. Thus, the sensitivity and specificity of the translated version, both were 83.3%. With this method, positive predictive value was 86.6%.
|Table 1: Results on the diagnosis via CHRLSq vs clinical diagnosis (N = 30 in each group)|
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However, without controlling the responses on item 6, that is, when the relief obtained with the movement was not controlled for the severity of RLS, the sensitivity dropped to 72.2%, but specificity increased to 86.7%, respectively. With this method, positive predictive value of the translated questionnaire was 83.3%.
Some problems were observed during linguistic translation as colloquial use of word differs from the literal translation. We chose to make it more user friendly as literal translation may limit the use of questionnaire in the clinical practice owing to the use of uncommon words and phrases [Table 2].
| Discussion|| |
The translated version of the CHRLSq, after controlling the response for item number 6, showed (Appendix 1 [Additional file 1]) 86.7% specificity and 72.2% sensitivity. Moreover, we have included population from different categories of occupations having varied level of education. Despite the fact that population belonged to such diverse background, none of them found any difficulty in understanding any of the items of the translated version.
Original instrument has also been designed to be more specific than the sensitive, similar to the results of this study.  However, the present translated version was found to be less specific and sensitive than the original questionnaire because of the difference in the populations in which the questionnaire was applied. The original questionnaire was applied to the population of blood donors not necessarily having RLS/WED, while in our study 20 out of 30 subjects in the RLS group were suffering from chronic persistent RLS and rest from chronic intermittent RLS.  In the original study, controls were not suffering from any of the conditions that mitigated RLS/WED; however, in this study, a sizable number of subjects (70%) in the control group were suffering from somatic symptoms disorder, which present with pains and aches involving various areas of the body. In such a context it is more important that the questionnaire picks up true cases, that is, need to be more specific. However, when we controlled the results for the item no 6 as discussed above, which asks for the relief obtained by the movement, the sensitivity decreased with a slight improvement in specificity. However, it must be remembered that this questionnaire was designed for the increased specificity; hence, it may miss some cases of the 'definite RLS/WED' when not accompanied by clinical examination which may be a limiting factor for its use in some of the studies. 
Original version had the positive predictive value of 85.5% and we found similar values (86.6 and 83.3%, respectively) by either of the methods suggesting that this instrument can be used in clinical settings. In conclusion, Hindi translation of the CHRLSq showed good specificity and positive predictive value. We did not find any problem during administration of this questionnaire in the population belonging to a diverse background, and thus it appears to be a useful tool for screening RLS/WED among the Indian Hindi speaking population.
| Acknowledgement|| |
We are thankful to Ms Anubha for helping us in the back translation of the questionnaire.
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[Table 1], [Table 2]