Clinical Impression of Severity Index for Parkinson's Disease and Its Association to Health-Related Quality of Life.

The CISI-PD provides a moderate correlation with the EQ-5D and could possibly be useful as a basis for defining health states in future health economic models and serving as outcomes in managed entry agreements. Nonetheless, the limitation of capturing nonmotor symptoms of the disease remains a shortcoming of clinical instruments, including the CISI-PD.