Winblad 2008 (combined)

Methods	See below for details of study 1 and study 2
Participants	See below for details of study 1 and study 2
Interventions	See below for details of study 1 and study 2
Outcomes	See below for details of study 1 and study 2
Notes	See below for details of study 1 and study 2
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "randomly assigned, 1:1"
Allocation concealment (selection bias)	Low risk	Quote: "Remote interactive voice response data‐entry system" used
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Quote: "double‐blind"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition dealt with by "a retrospective observational study" to identify vital status of all randomised participants: "retrieved dropout study"
Selective reporting (reporting bias)	Low risk	All outcomes reported
Other bias	Low risk	No additional biases