Table 2.
The results of subgroup analysis
| Outcome measures | Subgroup | The Num of studies |
Pooled estimate [SMD/MD (95 %CI)] |
P value | I2(%) | Test for subgroup differences | |
|---|---|---|---|---|---|---|---|
| global cognitive function | Treatment duration | ≤ 12 months | 7 | 0.35(-0.15, 0.84) | P = 0.17 | 87 | P = 0.67 |
| > 12 months | 8 | 0.23(0.07, 0.40) | P = 0.006 | 91 | |||
| participants | MCI patients | 5 | 0.82(0.20, 1.45) | P = 0.01 | 95 | P = 0.03* | |
| EAWCI | 10 | 0.13(0.03, 0.23) | P = 0.01 | 66 | |||
| information processing speed | Treatment duration | ≤ 12 months | 5 | -0.19(-0.38, 0.01) | P = 0.06 | 39 | P = 0.007* |
| > 12 months | 4 | 0.16(0.01, 0.31) | P = 0.04 | 64 | |||
| participants | MCI patients | 1 | 0.04(-0.28, 0.36) | P = 0.79 | NA | P = 0.89 | |
| EAWCI | 9 | 0.07(-0.13, 0.27) | P = 0.50 | 81 | |||
| episodic memory | Treatment duration | ≤ 12 months | 7 | -0.09(-0.27, 0.09) | P = 0.34 | 40 | P = 0.09 |
| > 12 months | 6 | 0.08(0.02, 0.13) | P = 0.01 | 0 | |||
| participants | MCI patients | 4 | 0.42(-0.24, 1.08) | P = 0.21 | 94 | P = 0.26 | |
| EAWCI | 11 | 0.04(-0.04, 0.12) | P = 0.34 | 28 | |||
| executive function | Treatment duration | ≤ 12 months | 4 | 0.01(-0.14, 0.17) | P = 0.87 | 0 | P = 0.21 |
| > 12 months | 5 | -0.29(-0.75, 0.16) | P = 0.20 | 96 | |||
| participants | MCI patients | 3 | -0.33(-0.81, 0.15) | P = 0.18 | 89 | P = 0.59 | |
| EAWCI | 8 | -0.17(-0.51, 0.17) | P = 0.34 | 94 | |||
| Hcy | Treatment duration | ≤ 12 months | 7 | -4.77(-6.28, -3.27) | P < 0.01 | 78 | P = 0.68 |
| > 12 months | 5 | -4.41(-5.27, -3.54) | P < 0.01 | 82 | |||
| participants | MCI patients | 3 | -5.45(-6.51, -4.39) | P < 0.01 | 81 | P = 0.05 | |
| EAWCI | 8 | -4.13(-4.93, -3.32) | P < 0.01 | 65 | |||
Abbreviations: SMD standardized mean difference, MD mean difference, CI confidence interval,MCI mild cognitive impairment, EAWCI elderly adults without cognitive impairment, Hcy Homocysteine, NA not applicable
*P < 0.05