Journal of Hand Therapy, 2025 (SCI-Expanded, Scopus)
Background: Manual dexterity impairments are among the most common and debilitating motor symptoms in Parkinson’s disease, significantly impacting patients’ quality of life. Assessment of dexterity is therefore critical for evaluating upper limb function and guiding therapeutic interventions. Purpose: To determine the test-retest reliability, minimum detectable change, concurrent, and discriminant validity of the Minnesota Manual Dexterity Test in people with Parkinson’s disease, and cut-off times that best distinguish people with Parkinson’s disease from healthy controls. Study Design: Cross-sectional study. Methods: Forty people with Parkinson’s disease and 30 healthy people were included. The test-retest reliability was evaluated by determining the intraclass correlation coefficient. The standard error of measurement and minimal detectable change were calculated by using intraclass correlation coefficient results. The concurrent validity of Minnesota Manual Dexterity Test was determined by investigating its relationship with the Nine-Hole Peg Test (9-NHPT), Jebsen Hand Function Assessment Test (JHFT), Unified Parkinson’s Disease Rating Scale, and Hoehn and Yahr scale. The cut-off times that best discriminated between people with Parkinson’s disease and healthy controls were investigated by plotting receiver operating characteristic curves. Results: The Minnesota Manual Dexterity Test demonstrated excellent test-retest reliability (intraclass correlation coefficient = 0.975-0.994). The minimum detectable change values of Minnesota Manual Dexterity Test subtests ranged from 7.26 to 12.39. Subtests showed fair to strong correlations with other outcomes (correlation coefficients ranged from 0.39 to 0.78, p ≤ 0.02). Significant differences in the Minnesota Manual Dexterity Test subtests were found between people with Parkinson’s disease and healthy controls (p < 0.001). Cut-off times ranging from 61.20 to 93.71 seconds were found to be good discriminants people with Parkinson’s disease from healthy controls. Conclusions: The Minnesota Manual Dexterity Test is a reliable and valid tool for assessing manual dexterity in people with Parkinson’s disease.