Comparative and Incremental Validity of NMSQuest, NMSS, and MDS-NMS With External Validation of a Conversion Equation in Parkinson’s Disease
Non-motor symptoms contribute to disability in Parkinson’s disease (PD), but instruments differ in format, content, and scoring. This study compared the Non-Motor Symptoms Questionnaire (NMSQuest), Non-Motor Symptoms Scale (NMSS), and Movement Disorder Society Non-Motor Rating Scale (MDS-NMS), externally evaluated the...