Table 2 Quality of evidence according to GRADE approach
Outcome indicator | No. studies (participants) | SMD (95%CI) | Bia of risk | Inconsistency | Indirectness | Imprecision | Publication bias | Evidence quality |
|---|---|---|---|---|---|---|---|---|
FSIQ | 4 (253) | −0.79[−1.42, −0.17] | Not serious | Serious a | Not serious | Not serious | None c | Very low |
VIQ | 2 (118) | −1.03[−2.20, 0.13] | Not serious | Serious a | Not serious | Serious b | None c | Very low |
Memory | 6 (351) | −0.41[−0.82, 0.00] | Not serious | Serious a | Not serious | Not serious | None c | Very low |
Attention | 2 (96) | −0.26[−0.69, 0.16] | Not serious | Not serious | Not serious | Serious b | None c | Very low |