Table 2. Neuropsychological testing at three time points for both drug and placebo groups.
| Drug group (n = 30) |
Placebo group (n = 30) |
Group |
Time |
Interaction |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean ± SD |
Mean ± SD |
Effect |
Effect |
Effect |
||||||||
| Baseline | 12 Months | 24 Months | Baseline | 12 Months | 24 Months | F value | P value | F value | P value | F value | P value | |
| General cognitive function | ||||||||||||
| MMSE | 26.00 ± 2.05 | 27.07 ± 1.95 | 26.68 ± 3.58 | 26.67 ± 1.45 | 25.57 ± 2.27 | 25.35 ± 3.01 | 4.171 | 0.046* | 1.677 | 0.192 | 11.943 | <0.001* |
| Episodic memory | ||||||||||||
| RAVLT N5 | 2.47 ± 2.05 | 4.52 ± 2.06 | 4.61 ± 1.89 | 4.23 ± 2.51 | 4.30 ± 2.76 | 4.55 ± 2.71 | 0.118 | 0.733 | 3.938 | 0.053 | 11.776 | 0.001* |
| RAVLT N1N5 | 18.93 ± 7.02 | 26.07 ± 6.83 | 23.82 ± 5.93 | 25.87 ± 8.74 | 25.77 ± 10.60 | 23.82 ± 9.53 | 0.281 | 0.599 | 2.825 | 0.064 | 11.154 | 0.001* |
| ROCF delay recall | 11.73 ± 5.84 | 13.17 ± 6.24 | 12.21 ± 5.83 | 9.77 ± 5.67 | 9.93 ± 6.01 | 7.66 ± 5.29 | 4.000 | 0.051 | 1.622 | 0.203 | 3.069 | 0.051 |
| Working memory | ||||||||||||
| Digit span | 10.57 ± 2.25 | 11.43 ± 1.78 | 10.21 ± 1.47 | 11.07 ± 1.84 | 10.53 ± 1.83 | 10.39 ± 1.61 | 0.053 | 0.818 | 0.596 | 0.444 | 5.937 | 0.018* |
| Backward digit span | 3.97 ± 1.33 | 4.83 ± 0.99 | 4.32 ± 0.90 | 4.13 ± 1.17 | 3.77 ± 0.82 | 3.43 ± 0.50 | 5.359 | 0.025* | 0.166 | 0.846 | 18.492 | <0.001* |
| Language function | ||||||||||||
| BNT | 23.13 ± 3.55 | 23.33 ± 3.44 | 23.50 ± 4.30 | 21.77 ± 3.74 | 22.80 ± 3.36 | 22.86 ± 4.91 | 0.756 | 0.388 | 2.393 | 0.128 | 0.532 | 0.469 |
| CVFT | 38.57 ± 8.05 | 42.43 ± 8.74 | 41.32 ± 8.82 | 42.37 ± 9.10 | 42.43 ± 7.68 | 41.93 ± 8.42 | 0.846 | 0.362 | 3.287 | 0.041* | 4.699 | 0.011* |
| Visuo-spatial ability | ||||||||||||
| ROCF-copy | 31.43 ± 4.59 | 31.61 ± 4.94 | 31.36 ± 5.72 | 30.90 ± 6.72 | 30.76 ± 6.32 | 28.76 ± 7.43 | 0.713 | 0.402 | 1.556 | 0.218 | 1.423 | 0.238 |
| CDT | 23.36 ± 3.52 | 23.54 ± 2.56 | 23.93 ± 3.98 | 23.48 ± 4.36 | 23.24 ± 4.53 | 23.14 ± 12.26 | 0.378 | 0.541 | 1.245 | 0.270 | 0.451 | 0.505 |
| Processing speed | ||||||||||||
| SDMT | 26.87 ± 10.30 | 28.77 ± 9.63 | 27.39 ± 10.30 | 31.47 ± 9.22 | 30.90 ± 10.60 | 30.00 ± 11.43 | 0.258 | 0.613 | 1.206 | 0.304 | 1.862 | 0.160 |
| TMT part A, sec | 70.23 ± 26.17 | 67.97 ± 24.19 | 74.93 ± 31.93 | 62.73 ± 25.04 | 61.20 ± 28.89 | 68.62 ± 30.11 | 0.045 | 0.833 | 5.966 | 0.004* | 0.230 | 0.795 |
| Stroop part A, sec | 32.17 ± 10.00 | 31.73 ± 7.52 | 32.36 ± 8.45 | 30.25 ± 8.36 | 30.39 ± 8.92 | 31.00 ± 11.31 | 0.024 | 0.877 | 0.333 | 0.717 | 0.077 | 0.926 |
| Stroop part B, sec | 46.10 ± 11.49 | 41.00 ± 7.66 | 43.36 ± 8.98 | 41.55 ± 11.20 | 41.38 ± 12.54 | 41.21 ± 13.36 | 0.004 | 0.949 | 1.004 | 0.321 | 2.783 | 0.101 |
| Executive function | ||||||||||||
| TMT part B, sec | 220.43 ± 76.79 | 195.97 ± 66.73 | 212.82 ± 54.85 | 212.50 ± 63.08 | 196.90 ± 89.20 | 212.69 ± 97.56 | 0.221 | 0.640 | 1.123 | 0.329 | 0.186 | 0.830 |
| Stroop part C, sec | 93.33 ± 23.71 | 80.80 ± 17.67 | 84.79 ± 18.36 | 81.14 ± 27.93 | 81.72 ± 28.96 | 83.50 ± 31.23 | 0.009 | 0.924 | 1.762 | 0.177 | 3.128 | 0.048* |
| TMT part B-A, sec | 150.20 ± 66.69 | 128.00 ± 57.15 | 137.89 ± 46.26 | 149.77 ± 50.97 | 135.70 ± 65.41 | 144.07 ± 79.05 | 0.522 | 0.473 | 1.697 | 0.198 | 0.129 | 0.721 |
| Stroop part C-B, sec | 47.23 ± 20.03 | 39.80 ± 15.81 | 41.43 ± 18.24 | 39.59 ± 21.58 | 40.35 ± 20.44 | 42.29 ± 25.06 | 0.007 | 0.932 | 1.285 | 0.281 | 1.693 | 0.189 |
Abbreviation: MMSE = Mini-Mental Status Examination; AVLT = Auditory Verbal Learning Test; ROCF = Rey-Osterrieth Complex Figure test; CDT = Clock-Drawing Test; CVFT = Category Verbal Fluency Test; BNT = Boston Naming Test; SDMT = Symbol Digit Modalities Test; SCWT = Stroop Color and Word Test; TMT = Trail Making Test. The comparisons of the neuropsychological scores between the two groups (drug and placebo) within three time points (baseline, 12 months and 24 months) were performed with the mixed-model ANOVA (2 × 3). Thereafter, the multiple comparisons were performed by F tests. P < 0.05 was considered as significant.