Study Year of publication Random sequence generation Allocation concealment Defined inclusion/
exclusion 		Blinding of participants and/
or personnel 		Blinding of
outcome assessment 		Incomplete outcome data Selective reporting
Juodzbalys et al. [30] 2008 N/A N/A + N/A N/A + +
Schlee et al. [33] 2009 + + + N/A N/A + +
Horowitz et al. [34] 2009 N/A N/A + N/A N/A + +
Jung et al. [35] 2018 - - + N/A N/A + +
Kim et al. [62] 2017 N/A N/A + N/A N/A + +

+ = low risk; N/A = unclear risk; - = high risk.