Translation of Parkinson's Disease Sleep Scale-2 (PDSS-2) in Hindi (H-PDSS-2) and its Validation for Assessment of Sleep Disturbances among Indian Parkinson's Disease Patients

Background and Objective: Parkinson's disease sleep scale-2 (PDSS-2) is a reliable sleep assessment tool which has been validated in several languages. As sleep problems have a great impact on the quality of life of Parkinson's disease patients, we aimed to translate and validate PDSS-2 in Hindi for its wider use among Hindi-speaking Indian patients. Our study objective was to translate PDSS-2 in Hindi (H-PDSS-2) and to assess the psychometric properties of H-PDSS-2 questionnaire for its use in Hindi-speaking Indian PD patients. Secondly, we aimed to compare the results with those of the other language PDSS-2 validation studies. Material and Methods: This study was done in two phases, enrolling 16 patients and 16 controls in the first/translation phase for assessment of internal consistency and discriminative power of PDSS-2. The test–retest reliability was determined in the second phase on 35 Parkinson's disease patients who were followed-up at an interval of 7–10 days. Results: No difficulties were faced by the patients and controls in the first phase, and internal consistency of the scale was good (Cronbach's alpha = 0.804). There was no significant difference in total H-PDSS-2 score at baseline 16.86 ± 10.59 and on retest 16.40 ± 9.54, suggesting good reliability. Intraclass correlation coefficients ranged from 0.710 to 0.901, and precision was 2.82 over the period of 7–10 days. Subdomains of H-PDSS-2 had moderate/high internal validity, and they showed significant correlation with Unified PD Rating Scale (UPDRS) and HY disease scale. Conclusion: H-PDSS-2 is equivalent to the original PDSS-2 for tested psychometric attributes. Its use among Indian Parkinson's disease patients will help in the comprehensive assessment of sleep problems among PD patients.