Table 3.
Main meta-analysis results presented by categories.
| Putative risk factor | N | N | Statistic | Random effects | Heterogeneity | Publication bias | ||
|---|---|---|---|---|---|---|---|---|
| Studies | FOG | No-FOG | Effect size (95%CI) | LOU effect size (95%CI), I2 | ||||
| Demographics and general characteristics | Age at baseline | 10 | 785 | 1596 | SMD | 0.11 (−0.07, 0.29) | Substantial | No |
| Age of PD onset | 8 | 899 | 1607 | SMD | 0.21 (0.12, 0.31)a | Small | No | |
| 6 | 490 | 2182 | HR | 1.01 (1.01, 1.02)a |
Considerable 1.01 (1.01, 1.02) a, I2 = 0% |
No | ||
| Age of PD onset (early PD = 1) | 4 | 450 | 949 | RR | 0.69 (0.35, 1.34) | Substantial | No | |
| Sex (Female = 1) | 21 | 1571 | 2949 | RR | 0.89 (0.78, 1.03) | Substantial | No | |
| 13 | 847 | 4434 | HR | 1.00 (0.93, 1.08) | Small | No | ||
| Education (Years) | 7 | 265 | 356 | SMD | −0.11 (−0.27, 0.06) | Small | No | |
| PD duration at baseline | 14 | 1117 | 2037 | SMD | 0.34 (0.11, 0.57)a |
Considerable 0.28 (0.06, 0.50)a, I2 = 83% |
No | |
| Motor features | Berg balance test score | 3 | 165 | 261 | SMD | −0.50 (−0.96, −0.05)a | Substantial | Yes |
| Hoehn and Yahr | 5 | 199 | 271 | SMD | 0.74 (0.24, 1.24)a |
Considerable 0.48 (0.22, 0.73)a, I2 = 0% |
No | |
| MDS-UPDRS Part 3 (OFF) | 3 | 253 | 368 | SMD | 0.64 (0.22, 1.07)a |
Considerable 0.37 (0.17, 0.57), I2 = 0% |
No | |
| MDS-UPDRS Part 3 (ON) | 3 | 78 | 130 | SMD | 0.59 (0.28, 0.90)a | Small | No | |
| MDS-UPDRS Part 3 (Unknown) | 4 | 498 | 807 | SMD | 0.38 (0.25, 0.50)a | Small | No | |
| UPDRS Part 3 (OFF) | 3 | 90 | 112 | SMD | 0.81 (0.52, 1.11)a | Small | No | |
| PD motor subtype (intermediate) | 3 | 208 | 279 | RR | 0.66 (0.19, 2.35) |
Considerable 0.95 (0.13, 6.77), I2 = 54% |
No | |
| PD motor subtype (PIGD) | 6 | 504 | 1048 | RR | 1.53 (0.86, 2.74) |
Considerable 1.20 (0.84, 1.71), I2 = 57% |
No | |
| PD motor subtype (tremor dominant) | 6 | 504 | 1048 | RR | 0.82 (0.68, 1.00) | Moderate | No | |
| PIGD score | 7 | 931 | 1659 | SMD | 0.60 (0.52, 0.68)a | Small | No | |
| Tremor score | 6 | 920 | 1648 | SMD | 0.01 (−0.09, 0.11) | Moderate | No | |
| Non-motor features | Geriatric Depression Scale | 6 | 609 | 799 | SMD | 0.32 (0.21, 0.42)a | Small | Yes |
| HAMA | 4 | 356 | 489 | SMD | 0.31 (0.09, 0.53)a | Substantial | No | |
| HAMD | 4 | 356 | 489 | SMD | 0.48 (0.34, 0.62)a | Small | No | |
| NMS-Quest | 3 | 165 | 162 | SMD | 0.85 (−0.31, 2.01) |
Considerable 0.33 (−0.34, 0.99), I2 = 47% |
No | |
| PDQ39 | 3 | 288 | 755 | SMD | 0.71 (0.57, 0.85)a | Small | No | |
| REM Sleep Behavior Disorder Questionnaire | 4 | 263 | 410 | SMD | 0.27 (0.11, 0.43)a | Small | No | |
| SCOPA-AUT | 3 | 228 | 380 | SMD | 0.38 (0.21, 0.54)a | Small | No | |
| State-Trait Anxiety Inventory | 5 | 583 | 768 | SMD | 0.22 (0.11, 0.33)a | Small | No | |
| Cognitive function | MMSE | 4 | 329 | 843 | SMD | −0.15 (−0.28, −0.02)a | Small | No |
| MOCA | 9 | 867 | 1302 | SMD | −0.21 (−0.35, −0.08)a | Substantial | No | |
| Medication | Amantadine use (Yes/No) | 4 | 475 | 984 | RR | 0.76 (0.33, 1.76) |
Considerable 1.23 (0.82, 1.84), I2 = 0% |
No |
| Dopamine agonist use (Yes/No) | 4 | 475 | 984 | RR | 0.59 (0.22, 1.54) |
Considerable 1.07 (0.95, 1.20) I2 = 0% |
No | |
| LEDD | 11 | 763 | 1505 | SMD | 0.54 (0.32, 0.77)a |
Considerable 0.48 (0.26, 0.69) a, I2 = 64% |
No | |
| 4 | 199 | 696 | HR | 1.00 (1.00, 1.00) |
Considerable 1.00 (1.00, 1.00), I2 = 30% |
No | ||
| Levodopa use (Yes/No) | 4 | 475 | 984 | RR | 1.54 (1.06, 2.25)a |
Considerable 1.23 (0.99, 1.52), I2 = 68% |
No | |
| Imaging | Caudate DAT | 4 | 535 | 741 | SMD | −0.38 (−0.50, −0.27)a | Small | No |
| Putman DAT | 3 | 467 | 626 | SMD | −0.34 (−0.46, −0.21)a | Small | No | |
| 7 | 312 | 1441 | HR | 0.86 (0.75, 0.99)a | Substantial | Yes | ||
ap < 0.05.