Table 3.

Risk of Bias for included studies

Author(s) (Year)	Sequence generation	Allocation sequence concealment	Masking of participants and personnela	Masking of outcome assessmenta	Incomplete data	Selective reporting	Other risks of bias
Eikeseth et al. (2002) [49]	High risk (availability of personnel)	High risk	High risk	Low risk	Low risk	Low risk	High risk (contamination, baseline imbalance)
Eikeseth et al. (2012) [50]	High risk (type of hospital/center)	High risk	High risk	High risk	High risk	High risk	High risk (contamination)
Eldevik et al. (2012) [51]	High risk (type of hospital/center)	High risk	High risk	Low risk	Unclear risk	Low risk	High risk (contamination)
Fava et al. (2011) [52]	High risk (parental preference)	High risk	High risk	High risk	Unclear risk	Low risk	High risk (contamination)
Fernell et al. (2011) [53]	High risk (post-hoc assignment)	High risk	High risk	High risk	High risk	Low risk	High risk (contamination, baseline imbalance)
Howard et al. (2005) [24]	High risk (Placement by educational team/ parents)	High risk	High risk	Unclear risk	High risk	Low risk	High risk (contamination, baseline imbalance)
Magiati et al. (2007) [54]	High risk (decision was made before study assignment)	High risk	High risk	Unclear risk	Low risk	Low risk	High risk (baseline imbalance)
Molnár et al. (2017) [55]	High risk (date of assignment)	High risk	High risk	High risk	Low risk	Low risk	Unclear risk (baseline imbalance)
Remington et al. (2007) [56]	High risk (parental preference)	High risk	High risk	Low risk	Unclear risk	Low risk	High risk (baseline imbalance)
Shawler (2016) [48]	Unclear risk	Unclear risk	High risk	Unclear risk	Low risk	Low risk	Low risk
Zachor & Ben-Itzchak (2010) [57]	High risk (place of residence)	High risk	High risk	High risk	Unclear risk	Low risk	Low risk

Note. ^aassessed for all outcomes combined, because they would all be affected by performance or detection bias in the same way