Table 3: Methodological quality of included RCTs.

Estimation of risk of bias Prasad K, et al. 2014 [18] Chen DC, et al. 2014 [46] Bang OY, et al. 2005 [59] Lee JS, et al. 2010 [60]
Allocation concealment Yes No Yes Yes
Blinding of outcomes Yes Yes Yes Yes
Intention-to-treat analysis Yes Yes No No
Losses to follow-up (incomplete outcome data addressed) Yes Yes No No