Assessment of Parkinson's disease levodopa-induced dyskinesia: a qualitative research study.

Background and objectives The 26-item Parkinson disease dyskinesia scale (PDYS-26) was developed to assess the impact of Parkinson’s disease levodopa-induced dyskinesias (PD-LID). The purpose of this qualitative research study was to assess the content validity of the PDYS-26 in an independent sample and to use the findings to suggest a conceptual framework around the impact of PD-LID.