Randomisation
An independent statistician at the Karolinska Institutet who was not involved in enrolling participants generated the randomisation sequence using Stata (Stata Statistical Software: Release 14. College Station, TX: StataCorp LP. 2015). Permuted block sizes of four were used. Randomisation was performed separately at the study sites using sequentially numbered opaque, sealed envelopes. Research assistants assessing trial eligibility did not open the envelope until after the participant was enrolled and had provided consent.