Minimal clinically important difference on the Motor Examination part of MDS-UPDRS

Parkinsonism Relat Disord. 2015 Dec;21(12):1421-6. doi: 10.1016/j.parkreldis.2015.10.006. Epub 2015 Oct 22.


Background: Recent studies increasingly utilize the Movement Disorders Society Sponsored Unified Parkinson's Disease Rating Scale (MDS-UPDRS). However, the minimal clinically important difference (MCID) has not been fully established for MDS-UPDRS yet.

Objective: To assess the MCID thresholds for MDS-UPDRS Motor Examination (Part III).

Methods: 728 paired investigations of 260 patients were included. At each visit both MDS-UPDRS and Clinician-reported Global Impression-Improvement (CGI-I) scales were assessed. MDS-UPDRS Motor Examination (ME) score changes associated with CGI-I score 4 (no change) were compared with MDS-UPDRS ME score changes associated with CGI-I score 3 (minimal improvement) and CGI-I score 5 (minimal worsening). Both anchor- and distribution-based techniques were utilized to determine the magnitude of MCID.

Results: The MCID estimates for MDS-UPDRS ME were asymmetric: -3.25 points for detecting minimal, but clinically pertinent, improvement and 4.63 points for observing minimal, but clinically pertinent, worsening.

Conclusions: MCID is the smallest change of scores that are clinically meaningful to patients. These MCID estimates may allow the judgement of a numeric change in MDS-UPDRS ME on its clinical importance.

Keywords: Clinician reported outcome; Minimal clinically important change; Minimal clinically important difference; Receiver operating characteristic curve; UPDRS.

Publication types

  • Comparative Study
  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Disease Progression
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Motor Activity*
  • Parkinson Disease / physiopathology*
  • ROC Curve
  • Sensitivity and Specificity
  • Severity of Illness Index*
  • Symptom Assessment
  • Treatment Outcome