Table 4.
The certainty of evidence by GRADE.
| Certainty assessment | No.of patients | Effect | Certainty | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| No.of studies | Study design | Risk of bias | Inconsistency | Indirectness | Imprecision | Other considerations | Dual task | Single task | Relative (95% CI) | Absolute (95% CI) | |
| 10 | Observational studies | Not seriousa | Not seriousb | Not seriousc | Seriousd | All plausible residual confounding would reduce the demonstrated effecte, f, g, h | 224 | 224 | - | SMD 0.34 (0.054 to 0.626) | ⊕⊕○○ Low |
CI, confidence interval; SMD, standardized mean difference.
aNo studies with high risk of bias were identified.
bThree studies showed inconsistent results, but the heterogeneity test I2 was < 10%.
cAll studies explored-the association directly.
dThe sample size of some studies was small and the confidence intervals were wide.
eThe funnel plot showed that there was no significant publication bias.
fThe effect sizes were interpreted as 0.2 for a small effect, 0.5 for a moderate effect, and 0.8 or greater for a large effect. This effect size was defined as small.
gThe two tasks were performed by the same subject to avoid the interference of factors such as the course of the disease, the degree of cognition and the degree of movement.
hNo study found a dose response gradient.
Study design represents the types of study designs, including randomized trial, observational study and any other evidence. Risk of bias represents the possible deviation between the results of a study and the real situation due to methodological problems. Inconsistency represents whether there are large differences in outcomes between studies.
Indirectness represents whether to compare the efficacy of two interventions directly and indirectly. Imprecision represents effect of the width of the confidence interval on the accuracy of the results. Certainty of evidence reflects the extent to which our confidence in an estimate of the effect is adequate to support a particular recommendation.
⊕⊕⊕⊕ represents “High”; ⊕⊕⊕○ represents “Moderate”; ⊕⊕○○ represents “Low”; ⊕○○○ represents “Very low”.