Table 3.
Baseline characteristics of subjects
| Variable | Total (n = 83) | Intervention group (A) (n = 41) | Control group (B) (n = 42) | P value (difference between A and B) | CDR = 0 (C) (n = 49) | CDR = 0.5 (D) (n = 34) | P value (difference between C and D) |
|---|---|---|---|---|---|---|---|
| For randomization | |||||||
| Age (y) | 80.5 ± 6.8 | 80.9 ± 7.2 | 80.2 ± 6.6 | .65 | 78.9 ± 5.5 | 82.8 ± 7.9 | .02 |
| Female gender (%) | 75.9 | 78 | 73.8 | .65 | 71.4 | 82.4 | .25 |
| High school completed or greater education (%) | 96.4 | 97.6 | 95.2 | .57 | 100 | 91.1 | .03 |
| CDR 0.5 (%) | 41 | 41.5 | 40.5 | .93 | — | — | — |
| Mini-mental state examination score | 28.3 ± 1.8 | 28.2 ± 1.7 | 28.3 ± 1.8 | .87 | 28.9 ± 1.3 | 27.3 ± 1.9 | <.0001 |
| Other (not for randomization) | |||||||
| Marital status (% married) | 46.3 | 45.0 | 47.6 | .81 | 52.1 | 38.2 | .21 |
| WRAT-R | 72.0 ± 12.1 | 72.0 ± 12.9 | 72.0 ± 11.5 | .75 | 75.1 ± 10.5 | 67.6 ± 13.2 | .007 |
| Used PC (%) | 14.6 | 15.0 | 14.3 | .99 | 10.4 | 12.6 | .82 |
| Primary outcome variables | |||||||
| Category fluency | 19.9 ± 5.1 | 19.5 ± 5.3 | 20.4 ± 4.9 | .42 | 21.8 ± 4.6 | 17.3 ± 4.6 | <.0001 |
| Letter fluency | 37.4 ± 13 | 37 ± 13.2 | 37.7 ± 12.9 | .82 | 39.1 ± 11.9 | 34.9 ± 14.1 | .16 |
| Word list acquisition | 19 ± 4.5 | 19 ± 4.8 | 18.9 ± 4.2 | .94 | 20.2 ± 3.7 | 17.2 ± 4.9 | .004 |
| Word list delayed recall | 4.8 ± 2.3 | 4.8 ± 2.2 | 4.8 ± 2.4 | .96 | 5.6 ± 2.0 | 3.6 ± 2.2 | <.0001 |
| Trail making test A | 41.3 ± 15.8 | 44.6 ± 17 | 38.0 ± 14.0 | .06 | 36.4 ± 11.3 | 48.6 ± 18.8 | .002 |
| Trail making test B | 120.1 ± 62.3 | 123.1 ± 60.5 | 117.4 ± 64.5 | .68 | 102.9 ± 45.7 | 144.5 ± 74.1 | .005 |
| Stroop test | 29.3 ± 8.7 | 29.9 ± 10.5 | 28.8 ± 6.5 | .55 | 32.0 ± 7.9 | 25.5 ± 8.5 | .001 |
| Cogstate computerized tests | |||||||
| Detection test (log of speed of performance) | 2.6 ± 0.1 | 2.6 ± 0.1 | 2.6 ± 0.1 | .45 | 2.6 ± 0.1 | 2.6 ± 0.1 | .72 |
| One back accuracy (working memory test) | 1.2 ± 0.2 | 1.2 ± 0.2 | 1.2 ± 0.1 | .75 | 1.2 ± 0.1 | 1.1 ± 0.2 | .09 |
| Two back accuracy (working memory test) | 1.1 ± 0.2 | 1.1 ± 0.1 | 1.1 ± 0.2 | .78 | 1.1 ± 0.2 | 1.0 ± 0.2 | .14 |
| CAMCI test, total score∗ | −0.05 ± 0.68 | −0.12 ± 0.78 | 0.03 ± 0.56 | .32 | 0.19 ± 0.45 | −0.38 ± 0.80 | .0004 |
| Secondary outcome variable | |||||||
| Loneliness score (range 3–9) | 4.0 ± 1.6 | 4.3 ± 1.9 | 3.6 ± 1.0 | .05 | 3.7 ± 1.2 | 4.3 ± 1.9 | .09 |
| Control variable | |||||||
| GDS-15 | 1.7 ± 2.2 | 2.0 ± 2.3 | 1.5 ± 2.1 | .30 | 1.5 ± 1.9 | 2.0 ± 2.5 | .37 |
| Exploratory analysis (NEO 5-factor personality scale) | |||||||
| Extraversion | 3.5 ± 0.8 | 3.4 ± 0.8 | 3.6 ± 0.8 | .16 | 3.5 ± 0.9 | 3.4 ± 0.8 | .47 |
| Agreeable | 4.3 ± 0.6 | 4.2 ± 0.7 | 4.4 ± 0.5 | .05 | 4.3 ± 0.6 | 4.3 ± 0.6 | .97 |
| Conscientious | 3.9 ± 0.7 | 4.0 ± 0.8 | 3.8 ± 0.6 | .46 | 3.9 ± 0.8 | 3.9 ± 0.7 | .68 |
| Neuroticism | 2.3 ± 0.8 | 2.4 ± 0.9 | 2.2 ± 0.7 | .15 | 2.3 ± 0.8 | 2.3 ± 0.8 | .77 |
| Openness | 4.0 ± 0.6 | 4.0 ± 0.6 | 4.0 ± 0.6 | .65 | 4.0 ± 0.6 | 4.0 ± 0.7 | .85 |
Abbreviations: CAMCI, computer assessment of mild cognitive impairment; GDS-15, geriatric depression scale, 15-item scale; WRAT-R, wide range achievement test-revised.
NOTE. Data presented as mean ± standard deviation or percentages.
∗
Z score compared with normative scores generated by the CAMCI, based on their normative distribution [8].