Study	Reason for exclusion
Chari 1994	This was a case series.
Diakomanolis 2002	Randomisation was not mentioned (this was a retrospective cohort study).
Friedrich 1971	Randomisation was not mentioned (this was a controlled study).
Li 2004	This was a phase 2 study, not a RCT.
Origoni 1996	Randomisation was not mentioned (this was a controlled study).
Skierlo 1987	This was a case series.
Sotiriou 2008	This was a case series.
Zarcone 1996	Randomisation was not mentioned (this was a retrospective cohort study).
Zhu 2006	This was not a RCT according to the Chinese content of the paper.