Author Random sequence
generation
Allocation
concealment
Patient
blinding
Outcome
blinding
Incomplete outcome
data addressed
Selective
reporting
Cosso et al. [34] ? + ? + ? +
Gorla et al. [35] + + ? + ? +
Xavier et al. [36] + + ? ? ? ?
Pereira et al. [37] + + ? + ? +

+ = low risk of bias; ÷ = high risk of bias; ? = unclear risk of bias.