Clinical evaluation, self-report, and medication inspection are used to document medical conditions. The diagnostic process is identical to that performed in the Religious Orders Study. Briefly, a decision tree designed to mimic expert clinical judgment was implemented by computer to inform several clinical diagnoses, including dementia and AD [32]. It combines data reduction techniques for the cognitive performance testing with a series of discrete clinical judgments made in series by a neuropsychologist and a clinician. Presumptive diagnoses of dementia and AD are calculated that conform to accepted clinical criteria [7]. The clinician is asked to agree or disagree with the decisions. An algorithm uses these decisions to provide diagnoses of MCI and amnestic MCI [33]. Persons with MCI are judged to have cognitive impairment by neuropsychologic testing without a diagnosis of dementia by the clinician. Persons without dementia or MCI are categorized as no cognitive impairment (NCI). A similar decision tree also is employed to aid the diagnosis of stroke, cognitive impairment due to stroke (vascular dementia), parkinsonism, Parkinson's disease (PD), and depression following accepted criteria [34–36]. The evaluation is
