For the topic of PD prognosis and progression Camilla posted two
of the PD rating scales, Hoehn & Yahr and the Independence
Assessment Scale . I believe that there are some problems with
the use of at least one of these scales as an indicator of disease
progression.
There is a big discrepancy between the scales regarding
"independence" and, perhaps, linearity. At Hoehn & Yahr stage 4,
which is 80% of the way to the final stage, a pwp has "severe
disability" but is "still" able to "function independently." On the
Independence Assessment Scale a pwp only 40% of the way to
the final stage already has "some dependency" ("some chores
[are] impossible") and a pwp is "very dependent" 60% of the way.
Independence doesn't seem to me to be a good indicator of
progression. I think one can be more or less independent at the
same level of disease progression by using or not using certain
methods and assistive devices and even by virture of attitude and
learned behavior patterns. Perhaps the independence scale should
be used as a measure of independence only, and not of
progression. The Hoehn & Yahr scale seems to be a better
indicator of disease pathology because it refers to symptoms.
Further, regarding the effect of medication, if a pwp is at different
levels on a scale depending on medication, then the ratings show
the effects of or responses to medication, not disease progression.
Shouldn't progression always be rated with the pwp unmedicated?
Has anyone else any thoughts about this?
Phil Tompkins
Hoboken NJ
age 62/dx 1990
