Objective: To identify individual Part III items that disproportionately contribute to first-attempt certification failure and to evaluate the stability of these patterns over five years.
Background: The MDS-UPDRS Part III Motor examination is a key outcome measure in Parkinson’s disease clinical trials and practice. While the certification program supports global standardization, the specific item-level contributors to certification failure have not been systematically examined at scale.
Method: We conducted a retrospective item-level analysis of certification examinations completed between 2019 and 2023. To minimize bias from repeated exposure, analyses were restricted to the first examination attempt per user per year (106,216 item observations). Failure rates were calculated for each item and examined within and across cases.
Results: Failure patterns were structured and reproducible rather than randomly distributed across items. The highest failure rates consistently involved limb bradykinesia tasks (finger tapping, hand movements, leg agility), tremor amplitude grading, facial expression, and speech. Constancy of rest tremor (Item 3.18) demonstrated the lowest overall pass rate (28.5%).
Case-specific analyses showed concentrated difficulty profiles: in Case 3, failures were driven primarily by lower-limb bradykinesia (leg agility 75.8%) and upper-limb decrement tasks; in Case 4, facial expression (79.28%) predominated. There was a difference on failure assessment on leg agility between left and right parts (37.43% vs 71.39%). Although several items showed statistically significant year associations, absolute differences were small, indicating stable difficulty structure over time.
Conclusion: Certification failure in the MDS-UPDRS motor examination is driven by a limited and reproducible subset of items. Recognition of these stable high- difficulty domains supports targeted refinement of training emphasis and reinforces the consistency of Part III scoring in multicenter clinical trials.
To cite this abstract in AMA style:
C. Falup-Pecurariu, C. Akbostanci, E. Bayram, I. Estrada-Bellmann, J. Ma, T. Mestre, I. Murasan, O. Ojo, P. Pal, M. Qamar, F. Rodriguez-Porcel, A. Sanchez Ferro. Item – Level Drivers of Certification Failure in the MDS-UPDRS Motor Examination: A Five-Year Global Analysis [abstract]. Mov Disord. 2026; 41 (suppl 1). https://www.mdsabstracts.org/abstract/item-level-drivers-of-certification-failure-in-the-mds-updrs-motor-examination-a-five-year-global-analysis/. Accessed October 1, 2026.« Back to 2026 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/item-level-drivers-of-certification-failure-in-the-mds-updrs-motor-examination-a-five-year-global-analysis/