aa Tam 2007b

Methods	see Tam 2007a (year 2)
Participants
Interventions
Outcomes
Funding Source
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number
Allocation concealment (selection bias)	Low risk	"At enrolment, each subject was assigned the next sequential subject number and received study product of the treatment code assigned to that subject number according to a preprinted randomisation allocation list"
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐blinding
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Possibility of biased follow‐up and reporting bias
Summary assessments	Low risk	Plausible bias unlikely to seriously alter the results