How is the prevalence of Parkinson's determined in the United States?
There is no National registry; the Ali foundation has a self reported
registry and a couple of states do have registeries, though nothing on a
national level. How is the prevalence determined? thank you, madelyn

*************

It is extrapolated from a sample size, just like a survey of 1,200 most likley voters can predict the results of a presidential election with a 5% margin of error.

Yours, Hubert H. Fernandez