Thomas 2003.

Methods	Same as Thomas 2002
Participants	Same as Thomas 2002
Interventions	Same as Thomas 2002
Outcomes	Same as Thomas 2002
Notes	The study by Thomas et al was reported twice as a conference abstract (Thomas 2002; Thomas 2003). We reported both the titles, but they describe the same study. We contacted the first author for further information, but received no response
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	Same as Thomas 2002