Table 3.
Summary of the meta-analytic results of the following cognitive dimensions.
| Domains/subgroups | K | PD-RBD | PD-NRBD | Effect size | Heterogeneity | ||
|---|---|---|---|---|---|---|---|
| SMD (P-value) | 95% CI | I2 (%) | P | ||||
| CONFIRMED-RBD | |||||||
| Global cognitive function | 17 | 625 | 708 | −0.41 (0.001) | −0.66 to −0.16 | 74 | <0.00001 |
| Memory—long-term verbal recall | 5 | 128 | 109 | −0.64 (0.02) | −1.16 to −0.11 | 70 | 0.009 |
| Memory—long-term verbal recognition | 3 | 93 | 74 | −0.50 (0.002) | −0.81 to −0.19 | 0 | 0.58 |
| Memory—short-term verbal recall | 2 | 35 | 35 | 0.15 (0.63) | −0.47 to 0.78 | 36 | 0.21 |
| EF—generativity | 5 | 128 | 109 | −1.12 (0.002) | −1.85 to −0.39 | 83 | 0.0001 |
| EF—inhibition | 5 | 128 | 99 | 0.63 (0.0007) | 0.27–1.00 | 36 | 0.18 |
| EF—shifting | 3 | 93 | 74 | 0.80 (<0.00001) | 0.48–1.12 | 0 | 0.66 |
| EF—updating | 4 | 110 | 93 | −0.39 (0.22) | −1.01 to 0.23 | 75 | 0.007 |
| Language | 2 | 68 | 55 | −0.49 (0.009) | −0.85 to −0.12 | 0 | 0.93 |
| Visuospatial/constructional ability | 3 | 93 | 74 | −0.61 (0.0001) | −0.92 to −0.30 | 0 | 0.99 |
| PROBABLE-RBD | |||||||
| Global cognitive function | 21 | 2025 | 3097 | −0.24 (0.0007) | −0.39 to −0.10 | 78 | <0.00001 |
| Memory—long-term verbal recall | 6 | 476 | 714 | −0.20 (0.18) | −0.49 to 0.09 | 81 | <0.0001 |
| Memory—long-term verbal recognition | 5 | 470 | 877 | 0.07 (0.64) | −0.21 to 0.34 | 80 | 0.0004 |
| Memory—short-term verbal recall | 2 | 111 | 73 | −0.23 (0.24) | −0.61 to 0.16 | 35 | 0.22 |
| EF—generativity | 7 | 763 | 1368 | 0.12 (0.49) | −0.22 to 0.45 | 92 | <0.00001 |
| EF—inhibition | 2 | 68 | 89 | 0.40 (0.27) | −0.31 to 1.11 | 79 | 0.03 |
| EF—shifting | 4 | 198 | 163 | 0.39 (0.0003) | 0.18–0.61 | 0 | 0.68 |
| EF—updating | 2 | 83 | 89 | −0.34 (0.11) | −0.76 to 0.08 | 46 | 0.17 |
| Visuospatial/constructional ability | 6 | 539 | 1117 | −0.04 (0.78) | −0.37 to 0.28 | 88 | <0.00001 |
| MIXED-RBD | |||||||
| Memory—long-term visual recall | 4 | 172 | 172 | −0.34 (0.002) | −0.55 to −0.12 | 0 | 0.70 |
| Memory—short-term spatial recall | 2 | 104 | 56 | −0.65 (0.001) | −1.04 to −0.26 | 19 | 0.27 |
| EF—general | 4 | 721 | 444 | −0.31 (0.02) | −0.57 to −0.06 | 46 | 0.13 |
| Processing speed/complex attention/working memory (LNS) | 4 | 412 | 802 | −0.01 (0.95) | −0.33 to 0.30 | 81 | 0.001 |
| Processing speed/complex attention/working memory (TMT: A) | 3 | 103 | 98 | 0.57 (<0.0001) | 0.29–0.86 | 0 | 0.82 |
| Psychomotor ability | 6 | 464 | 1084 | −0.31 (0.05) | −0.62 to 0.01 | 84 | <0.00001 |
Statistically significant values of effect size are reported in bold.
K, number of studies; PD-RBD, number of PD patients with RBD; PD-NRBD, number of PD patients without RBD; SMD, standardized mean difference; CI, confidence intervals; I2, heterogeneity statistics; EF, executive function; LNS, letter–number sequencing; TMT: A, trail making test: part A.