Validity
MCI
DISEASE
Convergent/discriminant validity (i.e., the degree to which a measure is associated with other measures/variables conceptually or based on the expected relationship with the chosen variable(s)) was assessed using screening/baseline data by examining correlations of the ADCS-ADL-MCI with various COA measures included in the trial. Specifically, the ADCS-ADL-MCI was anticipated to be at least moderately correlated (> 0.30) [Known-groups validity (i.e., the ability of an instrument to distinguish between different populations when a difference between them is expected) was examined at baseline (and at month 36 for consistency with the other psychometric tests) to determine whether the ADCS-ADL-MCI could distinguish between patients by disease severity within the MCI spectrum. Thereby, disease severity was defined in several ways: 1) 