Table 5. Quality assessment and risk of bias.

Study	Selection (out of 4)	Comparability (out of 2)	Outcome (out of 3)
Ling et al. [5]	3	2	3
Singhal et al. [6]	4	2	3
Choi et al. [7]	2	1	2
Wu et al. [8]	3	2	3
Cheng et al. [9]	4	2	3
Kraayvanger et al. [10]	2	1	2
Chen et al. [11]	4	2	3