title: Calibration of unified Parkinson's disease rating scale scores to Movement Disorder Society-unified Parkinson's disease rating scale scores.
abstract: The aim of this study was to develop formulas to convert the UPDRS to Movement Disorder Society (MDS)-UPDRS scores. The MDS-UPDRS is a revision of the UPDRS with sound clinimetric properties. Reliable formulas to recalculate UPDRS scores into MDS-UPDRS equivalents are pivotal to the practical transition and definitive adoption of the MDS-UPDRS. UPDRS and MDS-UPDRS scores were collected on 875 PD patients. A developmental sample was used to regress UPDRS scores on corresponding MDS-UPDRS scores based on three H & Y groupings (I/II, III, and IV/V). Regression weighting factors and intercept terms provided formulas for UPDRS conversions to be tested in a validation sample. Concordance between the true MDS-UPDRS Part scores and those derived from the formulas was compared using Bland-Altman's plots and Lin's concordance coefficient (LCC). Significant concordance between UPDRS-estimated MDS-UPDRS scores was achieved for Parts II (Motor Experiences of Daily Living) (LCC = 0.93) and III (Motor Examination) (LCC = 0.97). The formulas resulted in mean differences between the true MDS-UPDRS and estimated MDS-UPDRS scores of less than 1 point for both Parts II and III. Concordance was not achieved for Parts I and IV (Non-motor Experiences of Daily Living and Complications of Therapy). Formulas allow archival UPDRS Parts II and III individual patient data to be accurately transferred to MDS-UPDRS scores. Because Part I collects data on much more extensive information than the UPDRS, and because Part IV is structured differently in the two versions, old ratings for these parts cannot be converted. © 2012 Movement Disorder Society.
authors.affiliation: Rush University Medical Center, Chicago, Illinois, USA.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Goetz
authors.forename: Glenn T
authors.initials: GT
authors.lastname: Stebbins
authors.forename: Barbara C
authors.initials: BC
authors.lastname: Tilley
mesh_terms: D000465:Algorithms; D002138:Calibration; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D009069:Movement Disorders / Q000503:physiopathology*; D010300:Parkinson Disease / Q000150:complications / Q000175:diagnosis*; D012720:Severity of Illness Index; D012958:Societies, Scientific / Q000592:standards*