Table 4.
Mean difference in cognitive change between antioxidant and placebo groups by subgroups *
| Characteristics | Mean difference in cognitive change [Active Group – Placebo Group] (95% CI) |
||
|---|---|---|---|
| Vitamin E | Vitamin C | β−carotene | |
| Age at 1st assessment | |||
| ≤ 72 years (n=1440) | −0.03 (−0.09, 0.04) | 0.05 (−0.01, 0.12) | 0.03 (−0.03, 0.10) |
| > 72 years (n=1384) | 0.02 (−0.05, 0.08) | −0.01 (−0.08, 0.05) | 0.02 (−0.05, 0.09) |
| P†=0.34 | P=0.16 | P=0.80 | |
| 1st cognitive assessment score | |||
| Below median (n=1412) | −0.01 (−0.08, 0.06) | 0.05 (−0.02, 0.12) | 0.05 (−0.02, 0.12) |
| Above median (n=1412) | −0.01 (−0.07, 0.05) | 0.01 (−0.05, 0.07) | 0.00 (−0.06, 0.05) |
| P=1.00 | P=0.37 | P=0.21 | |
| Highest attained education | |||
| LPVN/AD/RN ‡ (n=1861) | −0.04 (−0.10, 0.01) | 0.03 (−0.03, 0.08) | 0.01 (−0.05, 0.06) |
| BA, MA, DR (n=788) | 0.06 (−0.03, 0.15) | −0.01 (−0.10, 0.08) | 0.04 (−0.05, 0.13) |
| P=0.05 | P=0.53 | P=0.50 | |
| Prevalent CVD event/Risk factors § | |||
| CVD event (n=2120) | 0.00 (−0.06, 0.05) | 0.04 (−0.01, 0.10) | 0.03 (−0.02, 0.09) |
| Risk factors (n= 704) | −0.01 (−0.10, 0.08) | −0.04 (−0.13, 0.05) | 0.00 (−0.09, 0.09) |
| P=0.91 | P=0.12 | P=0.51 | |
| Incident Cardiovascular disease ║ | |||
| Present (n= 501) | − 0.06 (−0.05, 0.17) | 0.15 (0.04, 0.26) | 0.00 (−0.11, 0.11) |
| Absent (n=2323) | −0.02 (−0.07, 0.03) | 0.00 (−0.05, 0.05) | 0.03 (−0.02, 0.08) |
| P=0.17 | P=0.009 | P=0.64 | |
| Dietary intake of specific antioxidant | |||
| “Low” ¶| | 0.01 (−0.05, 0.08) | −0.06 (−0.27, 0.14) | 0.14 (0.04, 0.24) |
| “Adequate” | −0.01 (−0.08, 0.05) | 0.03 (−0.02, 0.07) | 0.00 (−0.05, 0.06) |
| P=0.62 | P=0.40 | P=0.02 | |
| Cigarette smoking | |||
| Never smoker (n=1314) | −0.03 (−0.10, 0.04) | 0.00 (−0.07, 0.06) | 0.03 (−0.04, 0.10) |
| Ever smoker (n=1510) | 0.01 (−0.05, 0.07) | 0.04 (−0.02, 0.10) | 0.02 (−0.04, 0.09) |
| P=0.40 | P=0.34 | P=0.96 | |
| Alcohol drinking | |||
| Non-drinker (n=1416) | −0.01 (−0.08, 0.06) | 0.02(−0.04, 0.09) | 0.04 (−0.03, 0.11) |
| Drinker (n=1280) | 0.01 (−0.06, 0.08) | 0.02 (−0.05, 0.08) | 0.02 (−0.05, 0.08) |
| P=0.64 | P=0.85 | P=0.64 | |
| Multivitamin | |||
| Non-user (n=1970) | −0.01 (−0.06, 0.05) | 0.01 (−0.05, 0.06) | 0.02 (−0.04 0.07) |
| User (n= 833) | 0.00 (−0.09, 0.09) | 0.05 (−0.04, 0.13) | 0.03 (−0.05, 0.12) |
| P=0.91 | P=0.46 | P=0.79 | |
Characteristics as of randomization, except for cumulative cardiovascular disease which occurred during follow-up and compliance. “Mean difference in change in score” is defined as the change in the global composite score from baseline in the active group minus the change in the global composite score from baseline in the placebo group, with negative values indicating an adverse effect of the active agent.
P =p value for interaction for testing effect modification
LPVN: Licensed practical or vocational nurse; AD: Associate’s degree; RN: Registered nurse; BA: Bachelor’s degree; MA: Master’s degree; DR: Doctoral degree
Non-fatal MI, non-fatal stroke, revascularization surgery, or cardiovascular death as of randomization
“Incident cardiovascular disease” refers to an updated history of cardiovascular disease as of each follow-up assessment
“Low” dietary intake refers to intake from diet and supplements and is defined for vitamin C, as <75 mg/day (RDA; n=164), for vitamin E, as <15 mg/d (RDA; n=1315), for total carotenoids, as <3.09 mg/d (lowest quintile cutpoint; n= 539); “Adequate” refers to intakes greater than the cutpoints for “low”