Table 2.

Summary of risk of bias in all the randomized controlled trials including the results reported by de Jonge et al. [12], Ram et al. [25], and Kumar et al. [22], and the results of the systematic review by Stern et al. [13]. The risk of bias included randomization sequence, concealment, blinding of participant and clinician, incomplete outcome data, selective reporting, and others. The color of risk of bias: green, low risk of bias; yellow, unclear risk of bias; red, high risk of bias.

		Randomization Sequence	Concealment	Blinding of Participant and Clinician	Blinding of Outcome Assessment	Incomplete Outcome Data	Selective Reporting	Others
our analysis	de Jonge 2022 [12]	low	low	high	low	low	low	low
	Kumar 2020 [22]	low	low	high	low	low	low	low
	Ram 2021 [25]	low	low	high	unclear	low	unclear	unclear
Stern analysis	Aguilar-Guisado 2017 [19]	low	low	high	high	low	low	low
	Bjornsson 1977 [20]	unclear	unclear	high	high	low	high	low
	Klaassen 2000 [21]	low	low	low	low	low	low	low
	Pizzo 1979 [24]	unclear	unclear	high	high	low	high	unclear
	Pizzo 1982 [23]	unclear	unclear	high	high	low	high	unclear
	Rodriguez 1973 [26]	unclear	unclear	high	high	low	high	unclear
	Santolaya 1997 [28]	unclear	unclear	high	high	low	high	unclear
	Santolaya 2017 [27]	unclear	unclear	high	low	low	high	low
	low (%)	45.5	45.5	9.1	36.4	100.0	36.4	54.5
	unclear (%)	54.5	54.5	0.0	9.1	0.0	9.1	45.5
	high (%)	0.0	0.0	90.9	54.5	0.0	54.5	0.0