Publication:

Validation of the Indonesian version of the non-motor symptoms scale for Parkinson’s disease

Background Non-motor symptoms are common, have a wide range of symptoms, and have emerged as a key determinant of poor quality of life (QoL) in Parkinson’s disease (PD) patients, contributing to severe disability, and shortened life expectancy. However, although common, the non-motor symptoms of PD are often not well recognized and under-reported in clinical practice. This study aimed to translate the origin non-motor symptoms scale for PD (NMSS), which was written in English, into an Indonesian version and to evaluate its reliability and validity.

Methods Linguistic validation and psychometric analysis of the Indonesian version of NMSS were conducted in 70 patients with PD using a cross-sectional study. The acceptability, reliability, and construct validity of NMSS were analyzed. Test-retest reliability was assessed over a time interval of 14 days in all patients.

Results The 70 patients were assessed (median age 67.5 years; 57.1% males; median duration of illness 48 months; median Hoehn and Yahr stage: 3). Mean NMSS was 51.86 (SD 44.02; median 37). Neither floor nor ceiling effect was observed on the Indonesian version of the NMSS total score. Validity test using Pearson product moment showed all 9 domains Indonesian version of NMSS were valid (r=0.506-0.805, p<0.001). NMSS total score showed satisfactory reliability (Cronbach’s α coefficient on the total score was 0.852, the range for domains: 0.146-0.814).

Conclusions Indonesian version of NMSS showed good reliability and validity for the assessment of non-motor symptoms in PD patients in Indonesia.