Mild Cognitive Impairment: Statistical Models of Transition Using Longitudinal Clinical Data

Table 1

Criteria for state classification.

State	Definition
Normal cognition	No cognitive test score more than 1.5 standard deviations (SD) below the age-adjusted mean; absence of MCICC or Dementia (see below)
Test-based amnestic MCI (aMCITB)	At least one score more than 1.5 SD below the age-adjusted mean on the following measures of episodic memory: Wechsler Logical Memory, Benton Visual Retention Test (number correct or number of errors), a word list (Consortium to Establish a Registry in Alzheimer’s Disease word list or California Verbal Learning Test ) total learning score, delayed recall score, savings score, and the maximum recalled minus delayed recall score
Test-based mixed MCI (mMCITB)	At least one score more than 1.5 SD below the age-adjusted mean on the following measures of language and executive function: phonemic or category verbal fluency, Boston Naming Test (15-item), and Trail Making Tests A or B
Clinical consensus-based MCI (MCICC)	A cognitive complaint by the subject or informant, or evidence for longitudinal decline on cognitive test performance (at least 1.5 SD decline); generally intact global cognition; no or minimal functional impairment; not demented by DSM-IV criteria; neurodegenerative etiology suspected
Dementia	Meeting DSM-IV criteria for dementia, or NINCDS/ARDRA criteria for possible or probable AD, or NINDS-AIREN criteria for possible or probable vascular dementia, or DLB Consortium criteria for Lewy body disease