ADAS-Cog assesses a range of cognitive abilities including memory, comprehension, orientation in time and place and spontaneous speech. Most items are evaluated by tests, but some are dependent on clinician ratings on a five point scale. The ADAS-Cog total score is the sum of the calculated scores for Questions 1 (Word recall task), 2 (Naming objects and fingers), and 7 (Word recognition task) and the scores recorded on the CRF for Questions 3 to 6 (Commands, Constructional praxis, Ideational praxis, Orientation) and 8 to 11 (Remembering test instructions, Spoken language ability, Word finding difficulty in spontaneous speech, Comprehension). The total score ranges from 0-70 with higher scores indicating greater dysfunction while lower indicates better cognitive function. Baseline was defined as the value at Week 0. Change from Baseline was obtained by subtracting the Baseline value from the post-randomization value at Week 24.

The CIBIC+ is a rating scale derived from an interview with the participant and caregiver with an independent rater designed to measure several domains of participant function, such as mental/cognitive state, behavior, and functioning. The scores are rated on a scale of 1 to 7 as follows: 1 (marked improvement), 2 (moderately improved), 3 (minimally improved), 4 (no change), 5 (minimally worse), 6 (moderately worse) and 7 (markedly worse).

The CDR-SB is an interviewer administered scale and impairment is scored in each of categories: memory, orientation, judgment and problem solving, community affairs, home and hobbies and personal care. Impairment is scored on a scale in which none = 0, questionable = 0.5, mild = 1, moderate = 2 and severe = 3. The 6 individual category ratings, or "box scores", were added together to give the CDR-Sum of Boxes which ranges from 0-18 (severe impairment). If there were any missing items then CDR-SB was set to missing and was not imputed. The change from Baseline was obtained by subtracting the Baseline value from the post-randomization value. Baseline was Week 0 value. Data for adjusted mean has been presented.