Cross‐Cultural Differences of the Non‐Motor Symptoms Studied by the Traditional Chinese Version of the International Parkinson and Movement Disorder Society–Unified Parkinson's Disease Rating Scale

Background Given the importance of ethnic differences in the evaluation of various aspects of symptoms in patients with Parkinson's disease (PD), we present the formal procedure for completing the traditional Chinese translation of the International and Parkinson and Movement Disorder Society/UPDRS (MDS-UPDRS) and highlight the discrepancy in nonmotor symptoms (NMS) between patients in Eastern and Western countries. Methods A total of 350 native Chinese-speaking PD patients were recruited from multiple hospitals in Eastern countries; they completed the MDS-UPDRS. The translation process was executed and factor analysis was performed to determine the structure of the scale. Chi-squared and t tests were used to compare frequency and severity of PD symptoms between the Chinese-speaking and English-speaking groups (n = 876). Results NMS and motor symptoms were more severe in the Western population (Part I: t(1205) = 5.36, P < 0.0001; and Part III: t(1205) = 7.64, P < 0.0001); however, the prevalence of cognitive dysfunction and impairments in activities of daily living were more frequent in the Eastern patients. The comparative fit index was 0.93 or greater, and the exploratory factor analysis revealed compatible results between the translated scale and the original version. Conclusion The traditional Chinese version of the MDS-UPDRS can be designated as an official translation of the original scale, and it is now available for use. Moreover, NMS in PD constitute a major issue worldwide, and the pattern of NMS among the Chinese population is more marked in terms of cognition-based symptoms and activities of daily living.