IPMDS-Sponsored Scale Translation Program: Process, Format, and Clinimetric Testing Plan for the MDS-UPDRS and UDysRS

We present the methodology and results of the clinimetric testing program for non-English translations of International Parkinson and Movement Disorder Society (MDS)–sponsored scales. The programs focus on the MDS revision of the UPDRS (MDS-UPDRS) and the Unified Dyskinesia Rating Scale (UDysRS). The original development teams of both the MDS-UPDRS and UDysRS envisioned official non-English translations and instituted a rigorous translation methodology. The formal process includes five core steps: (1) registration and start-up; (2) translation and independent back-translation; (3) cognitive pretesting to establish that the translation is clear and that it is comfortably administered to and completed by native-speaker raters and patients; (4) field testing in the native language using a large sample of Parkinson's disease patients; and (5) full clinimetric testing. To date, the MDS-UPDRS has 21 active language programs. Nine official translations are available, having completed all phases successfully, and the others are in different stages of development. For the UDysRS, 19 programs are active, with three official translations now available and the rest in development at different stages. Very few scales in neurology and none in movement disorders have fully validated translations, and this model may be adopted or modified by other scale programs to allow careful validation of translations. Having validated translations allows for maximal homogeneity of tools utilized in multicenter research or clinical trial programs.