Fig. 2.

Percent mean annual change in the total score (a) and effect size of the yearly change in the total score (b) according to the number of items included in the scale. The dotted line shows the corresponding values for an 11-item abridged version of the UMSARS, showing that further addition of items does not increase its sensitivity to change. Note that this is only a quick example showcasing the feasibility of improving the UMSARS and developing a new clinical outcome assessment (COA) tool for MSA that can be used in future clinical trials of disease modification. We are not proposing using this 11-item UMSARS instead of the conventional UMSARS. A proper development and validation process for the new COA will be necessary