aa Beutner 1979b.

Methods	See aa Beutner 1979a
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	Coded, identical‐looking compounds
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐blinding
Incomplete outcome data (attrition bias) All outcomes	Low risk	No losses to follow‐up
Summary assessments	Low risk	Plausible bias unlikely to seriously alter the results.