TABLE 2.
Cognitive function at two assessments by N‐3 supplement assignment, for VITAL‐Cog participants aged 60+ years, (n = 3424) assessed by telephone and for CTSC‐Cog participants aged 60+ years, (n = 794) assessed in person*
| VITAL‐COG (n = 3424; telephone assessments) | CTSC‐COG (n = 794; in‐person assessments) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| N‐3 group | Placebo group | Difference in score at each timepoint (N3 group – placebo group;95% CI) ‡ | N‐3 group | Placebo group | Difference in score at each timepoint (N3 group – placebo group; 95% CI) ‡ | ||||||
| N | Mean (SE) ‡ | N | Mean (SE) ‡ | N | Mean (SE) ‡ | N | Mean (SE) ‡ | ||||
|
Primary outcome: Global composite score † |
Difference in score ‡ |
Primary outcome: Global composite score † |
Difference in score ‡ | ||||||||
| First assessment score | 14980 | –0.03 (0.01) | 1486 |
–0.02 (0.01) |
–0.01 (–0.05, 0.03) | First assessment score ‡ | 385 | –0.03 (0.03) | 391 |
0.02 (0.03) |
–0.05 (–0.13, 0.03) |
| Second assessment score | 1440 | –0.28 (0.02) | 1483 |
–0.26 (0.01) |
–0.02 (–0.07, 0.02) | Second assessment score ‡ | 251 | 0.06 (0.03) | 264 |
0.11 (0.03) |
–0.05 (–0.14, 0.04) |
| Secondary outcomes | Secondary outcomes | ||||||||||
| Verbal composite score † | Difference in score ‡ | Verbal composite score † | Difference in score ‡ | ||||||||
| First assessment score | 14980 | –0.01 (0.02) | 1486 |
–0.01 (0.02) |
0.0003 (–0.05, 0.05) | First assessment score ‡ | 385 | –0.02 (0.04) | 391 |
0.02 (0.03) |
–0.04 (–0.14, 0.05) |
| Second assessment score | 1440 | –0.05 (0.02) | 1483 |
0.01 (0.02) |
–0.05 (–0.11, 0.002) | Second assessment score ‡ | 251 | 0.12 (0.04) | 264 |
0.16 (0.04) |
–0.05 (–0.17, 0.07) |
|
Executive function/ |
Difference in score ‡ |
Executive function/ |
Difference in score ‡ | ||||||||
| First assessment score | 14980 | –0.03 (0.02) | 1486 |
–0.01 (0.02) |
–0.01 (–0.06, 0.03) | First assessment score ‡ | 385 | –0.02 (0.04) | 391 |
0.01 (0.04) |
–0.03 (–0.13, 0.07) |
| Second assessment score | 1440 | –0.50 (0.02) | 1483 |
–0.52 (0.02) |
0.01 (–0.03, 0.06) | Second assessment score ‡ | 251 | –0.02 (0.04) | 264 |
0.02 (0.04) |
–0.04 (–0.14, 0.06) |
| TICS | Difference in score ‡ | 3MS | Difference in score ‡ | ||||||||
| First assessment score | 14980 | 33.85 (0.07) | 1486 |
33.88 (0.07) |
–0.03 (–0.23, 0.17) | First assessment score ‡ | 385 | 94.45 (0.24) | 391 |
95.21 (0.22) |
–0.76 (–1.41, –0.11) |
| Second assessment score | 1440 | 33.82 (0.08) | 1483 |
34.07 (0.07) |
–0.25 (–0.46, ‐0.05) | Second assessment score ‡ | 251 | 95.34 (0.25) | 264 |
95.87 (0.22) |
–0.53 (–1.19, 0.12) |
Abbreviations: 3MS, Modified Mini‐Mental State Examination (range = 0–100); CI, confidence interval; CTSC, Clinical and Translational Science Center for VITAL in Boston, MA; SE, standard error; TICS, Telephone Interview of Cognitive Status (range = 0–41); 19 VITAL, Vitamin D and Omega‐3 Trial.
In the VITAL‐Cog, 2483 completed both assessments, 501 completed only the baseline, 440 completed only the second assessment. In the CTSC‐Cog, 497 completed both assessments, 279 completed only the baseline, and 18 completed only the second assessment.
In the VITAL‐Cog: global score is a composite score representing the mean of the z‐scores of eight tests: TICS (range 0–41), immediate and delayed recalls of the East Boston Memory Test, category fluency (animal naming test), delayed recall of the TICS 10‐word list, Oral Trail Making Test A, Oral Trail Making Test B, and digit span backward. Verbal memory score is a composite score representing the mean of the z‐scores of four tests: the immediate and delayed recalls of both the TICS 10‐word list and the East Boston Memory Test. Executive function/attention score is a composite score representing the mean of the z‐scores of four tests: Trail Making Test A and B, category fluency tests (naming animals), and digit‐span backward. In the CTSC‐Cog: the global score is a composite score representing the mean of the z‐scores of nine tests: 3MS, immediate and delayed recalls of the East Boston Memory Test, category fluency tests (naming animals and vegetables), the immediate and delayed recalls of a 10‐word list and Trail Making Tests A and B. Verbal memory score was defined the same way as in VITAL‐Cog. Executive function/attention score is a composite score representing the mean of the z‐scores of four tests: Trail Making Tests A and B, category fluency tests (naming animals and vegetables).
Least squares means and standard errors and differences of least squares means and standard errors were derived from univariate models.