Slightly puzzling, probably from lack of full study information. At "initial examination" presumably means on entry into trial? And 51 participants had dementia? But no measure of dementia actually given? Or average duration since diagnosis of those with dementia? I am not so interested in those who became demented during the course of the study, because unless you know what start point was established, and how variable the participants were, then how do you glean anything from the results. For instance was this an elderly cohort, were they studied because they were already in care facilities (I have seen a lot of studies like that), or were they a more random sampling?

It is not just the figures that look a little odd, but there is no mention of what criteria is used to define dementia. Hallucinations are mentioned, and these can equally happen because of medication side effects as they can as an intrinsic part of Parkinson Disease. On their own I am not sure they are a measure of dementia. People with schizophrenia for instance have hallucinations but are not regarded as having dementia.

While this is a serious factor for PwP, I would like to know more detail of such studies than the bare bones, 'scarey', % basis on which this one is discussed.