Validation of an Arabic version of the Cambridge-Hopkins diagnostic questionnaire for restless legs syndrome

Purpose To validate an Arabic version of the short form of the Cambridge-Hopkins diagnostic questionnaire for restless legs syndrome (CH-RLSq13). Methods The Arabic version was created using a standard forward-backward translation method. A pre-final Arabic version was administered with the original English version to a group of bilingual subjects as a pretest. The inter-rater agreement between these two versions was measured. A finalized Arabic version was obtained. For the validation, the Arabic version of the CH-RLSq13 was administered to Lebanese subjects, above 18 years old, selected upon a clinical interview. The diagnosis provided by the Arabic version of the CH-RLSq13 was compared to the clinical diagnosis made by a neurologist at Hotel-Dieu de France hospital. Inter-rater agreement was assessed using Cohen's kappa coefficient. Sensitivity, specificity, and positive and negative predictive values of the translated questionnaire were calculated. Results Inter-rater agreement, between the 2 versions, for the entire questionnaire, was excellent (kappa = 0.950). All items showed a substantial level of agreement between the two versions. In the validation process, 91 participants were included (17 patients diagnosed with RLS and 74 control subjects). The mean age was 40 years, with female predominance. The final Arabic version of the CH-RLSq13 had a sensitivity of 71%, a specificity of 100%, and with negative and positive predictive values of 94% and 100% respectively. Conclusion The Arabic version of the CH-RLSq13 is a reliable tool for the screening and diagnosis of RLS in Lebanese and Arabic-speaking populations.