Table 2.
Mean difference in cognitive function at each cognitive assessment for each antioxidant
| VITAMIN E | VITAMIN C | β-CAROTENE | |||||
|---|---|---|---|---|---|---|---|
| Mean difference in score | Mean difference in score | Mean difference in score | |||||
| Cognitive Assessment |
N | [Active Group – Placebo Group] |
p-value | [Active Group – Placebo Group] |
p-value | [Active Group – Placebo Group] |
p-value |
| (95% CI) * | (95% CI) | (95% CI) | |||||
| PRIMARY ENDPOINT: Global score† (difference in score associated with being 1 year older = −0.03) | |||||||
| 1 | 2824 | −0.01 (−0.06, 0.04) | 0.71 | 0.05 (0.00, 0.10) | 0.05 | −0.03 (−0.08, 0.02) | 0.19 |
| 2 | 2511 | 0.00 (−0.06, 0.06) | 0.94 | 0.05 (−0.01, 0.11) | 0.09 | 0.00 (−0.06, 0.05) | 0.89 |
| 3 | 2271 | −0.02 (−0.09, 0.05) | 0.55 | 0.05 (−0.01, 0.12) | 0.10 | 0.01 (−0.06, 0.07) | 0.82 |
| 4 | 1586 | −0.05 (−0.13, 0.02) | 0.17 | 0.13 (0.06, 0.20) | 0.0005 | −0.01 (−0.09, 0.06) | 0.71 |
| KEY SECONDARY ENDPOINT: Verbal memory score† (difference in score associated with being 1 year older = −0.03) | |||||||
| 1 | 2824 | 0.02 (−0.03, 0.07) | 0.43 | 0.05 (0.00, 0.10) | 0.06 | −0.01 (−0.07, 0.04) | 0.62 |
| 2 | 2511 | 0.02 (−0.04, 0.09) | 0.45 | 0.05 (−0.01, 0.11) | 0.13 | 0.00 (−0.06, 0.06) | 0.99 |
| 3 | 2271 | −0.01 (−0.08, 0.06) | 0.75 | 0.07 (0.00, 0.13) | 0.05 | 0.02 (−0.04, 0.09) | 0.50 |
| 4 | 1586 | −0.06 (−0.13, 0.02) | 0.13 | 0.14 (0.06, 0.21) | 0.0004 | −0.02 (−0.09, 0.06) | 0.68 |
| TICS score† (difference in score associated with being 1 year older = −0.13) | |||||||
| 1 | 2824 | −0.01 (−0.25, 0.23) | 0.95 | 0.16 (−0.08, 0.39) | 0.20 | −0.18 (−0.42, 0.06) | 0.14 |
| 2 | 2511 | 0.03 (−0.23, 0.29) | 0.80 | 0.15 (−0.11, 0.41) | 0.24 | 0.06 (−0.20, 0.32) | 0.63 |
| 3 | 2270 | 0.08 (−0.37, 0.21) | 0.61 | 0.15 (−0.14, 0.44) | 0.31 | 0.14 (−0.15, 0.43) | 0.35 |
| 4 | 1586 | −0.16 (−0.49, 0.16) | 0.33 | 0.46 (0.14, 0.78) | 0.006 | −0.13 (−0.46, 0.19) | 0.42 |
| Category fluency score (difference in score associated with being 1 year older = −0.18) | |||||||
| 1 | 2819 | −0.42 (−0.78, −0.06) | 0.02 | 0.03 (−0.33, 0.39) | 0.87 | −0.22 (−0.58, 0.14) | 0.23 |
| 2 | 2504 | −0.45 (−0.83, −0.06) | 0.02 | 0.03 (−0.36, 0.41) | 0.90 | −0.05 (−0.44, 0.34) | 0.80 |
| 3 | 2261 | −0.25 (−0.66, 0.16) | 0.24 | 0.05 (−0.36, 0.46) | 0.80 | −0.05 (−0.46, 0.36) | 0.80 |
| 4 | 1583 | −0.35 (−0.80, 0.10) | 0.13 | 0.25 (−0.20, 0.70) | 0.27 | −0.01 (−0.46, 0.44) | 0.96 |
*
From longitudinal linear models of adjusted mean cognitive performance
†
TICS = Telephone Interview of Cognitive Status; Verbal score is a composite score of the z-scores of the immediate and delayed recalls of both the TICS 10-word and the East Boston Memory Test; Global score is a composite score of the z-scores of TICS, immediate and delayed recalls of the East Boston Memory Test, category fluency, delayed recall of the TICS 10-word list