Objective: To determine the metric properties of the non-motor symptoms questionnaire (NMSQuest), non-motor symptoms scale (NMSSS) and SCOPA-AUT clinimetric instruments to assess non motor dysfunction in Mexican population.
Material and methods: After linguistic validation, the instruments were applied to 100 consecutive Parkinson's disease patients to analyze its metric properties in Mexican out-patients from the National Institute of Neurology and Neurosurgery.
Results: Internal consistency by Cronbach's alpha was above 0.80 for all instruments. Inter-item and item-total correlations were above 0.30 in the majority of the domains and inter-observer variability was acceptable. Total score did not correlate with any of the registered clinical variables.
Conclusion: The metric properties of the three instruments were acceptable and similar to published data from other countries.