Table 1.
Baseline subject characteristics across demographic, clinical, and neurocognitive measures.
| Open Group (n=49) | Placebo-controlled Group—drug (n=51) | Placebo-controlled Group—placebo (n=8) | Between-Group Difference | |||||
|---|---|---|---|---|---|---|---|---|
| Characteristic | n | Mean ± SD or % | n | Mean ± SD or % | n | Mean ± SD or % | Test Statistic (DF) | p-value |
| Demographicsa | ||||||||
| Age | 49 | 69.2 ± 7.2 | 51 | 70.7 ± 8.4 | 8 | 73.9 ± 7.2 | F(2,105)=1.41 | 0.248 |
| Sex | χ2(2)=0.46 | 0.793 | ||||||
| Male | 17 | 34.7 | 19 | 37.3 | 2 | 25.0 | ||
| Female | 32 | 65.3 | 32 | 62.7 | 6 | 75.0 | ||
| Race | χ2(8)=3.00 | 0.935 | ||||||
| Asian | 1 | 2.0 | 0 | 0.0 | 0 | 0.0 | ||
| Black | 8 | 16.3 | 6 | 11.7 | 1 | 12.5 | ||
| White | 34 | 69.4 | 35 | 68.6 | 5 | 62.5 | ||
| Multiracial | 3 | 6.1 | 6 | 11.7 | 1 | 12.5 | ||
| Do not know | 3 | 6.1 | 4 | 7.8 | 1 | 12.5 | ||
| Ethnicity | χ2(2)=2.16 | 0.339 | ||||||
| Not Hispanic/ Latino | 38 | 77.6 | 45 | 88.2 | 7 | 87.5 | ||
| Hispanic/Latino | 11 | 22.4 | 6 | 11.8 | 1 | 12.5 | ||
| Years of education | 44 | 16.5 ± 2.7 | 42 | 16.2 ± 3.1 | 8 | 17.3 ± 2.1 | F(2,91)=0.53 | 0.593 |
| Baseline Depression measuresb | ||||||||
| 24-item Hamilton Rating Scale for Depression | 49 | 22.9 ± 6.3 | 51 | 23.6 ± 6.1 | 8 | 22.8 ± 4.9 | F(2,105)=0.19 | 0.824 |
| Quick Inventory of Depressive Symptomatology | 49 | 13.0 ± 4.7 | 50 | 13.5 ± 4.5 | 8 | 12.4 ± 4.4 | F(2,104)=0.32 | 0.718 |
| Clinical Global Impressions—Severity | 49 | 4.1 ± 0.6 | 51 | 3.9 ± 0.7 | 8 | 4.1 ± 0.6 | F(2,105)=0.86 | 0.427 |
| Baseline Expectancy measuresc | ||||||||
| Credibility and Expectancy Scale—Item 2 (Better) | 47 | 5.3 ± 1.3 | 46 | 46 5.5 ± 1.2 | 8 | 6.0 ± 1.1 | F(2,98)=0.99 | 0.377 |
| Credibility and Expectancy Scale—Item 4 (Depression) | 47 | 5.9 ± 0.9 | 46 | 6.0 ± 0.9 | 8 | 6.3 ± 1.2 | F(2,98)=0.65 | 0.526 |
| Baseline Cognitive measuresd | ||||||||
| Stroop Word | 49 | 89.7 ± 17.2 | 50 | 89.8 ± 16.0 | 8 | 83.1 ± 14.2 | F(2,104)=0.59 | 0.555 |
| Stroop Color | 49 | 59.0 ± 12.5 | 50 | 58.4 ± 11.4 | 7 | 55.1 ± 7.2 | F(2,103)=0.33 | 0.718 |
| Stroop Color Word | 49 | 32.6 ± 11.0 | 50 | 31.0 ± 9.0 | 7 | 31.7 ± 6.1 | F(2,103)=0.32 | 0.730 |
| Dementia Rating Scale—Initiation/Perseveration subscale score | 48 | 35.7 ± 2.7 | 50 | 35.2 ± 2.9 | 8 | 34.5 ± 5.6 | F(2,103)=0.67 | 0.516 |
| Digit Symbol Test | 49 | 38.9 ± 11.6 | 50 | 40.3 ± 10.3 | 8 | 35.4 ± 7.7 | F(2,104)=0.80 | 0.452 |
| Logical memory (WMS-R) delayed raw score | 49 | 13.2 ± 4.1 | 51 | 12.3 ± 4.8 | 8 | 12.1 ± 5.4 | F(2,105)=0.67 | 0.511 |
| Wechsler Test of Adult Reading (WTAR) | 48 | 42.9 ± 7.3 | 48 | 43.9 ± 6.1 | 7 | 43.7 ± 6.4 | F(2,100)=0.26 | 0.770 |
SD – standard deviation, DF – degrees of freedom.
a
One subject missing race information was recoded as “Do not know”. 14 subjects missing education.
b
One subject missing QIDS Depression.
c
Seven subjects missing baseline expectancy measures.
d
Two subjects missing baseline Stroop Color Word, Stroop Color, and Dementia Rating Scale—initiation/perseveration subscale score. One subject missing Digit symbol test score. Five subjects missing WTAR.