Table 3. Risk of bias in included studies.

Trial ID	Sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessors	Incomplete outcome data	Selective outcome reporting	Other source of bias	Industry sponsorship
Nakamura/1999	Unclear	Unclear	High	Unclear	Unclear	Unclear	Low	Unclear
Nemoto/2001	Unclear	Unclear	High	Unclear	Unclear	Unclear	Low	Unclear
Suzuki/2002	Unclear	Unclear	High	Unclear	Unclear	Low	Low	Unclear
Vincent/2005	Low	Low	High	Unclear	Low	Unclear	Low	Unclear
Cruz/2009	Low	Low	High	Low	Low	Low	Low	Yes
Payen/2015	Low	Low	High	Low	Low	Low	High	Yes
Srisawat/2016	Unclear	Unclear	Unclear	Unclear	Low	Low	Unclear	Unclear