Incomplete outcome data
We recorded the proportion of participants whose outcomes were
analysed. We coded loss to follow-up for each outcome as:
• Low risk: if fewer than 20% of patients were lost to followup
and reasons for loss to follow-up were similar in both
treatment arms;
• Unclear risk: if loss to follow-up was not reported;
• High risk: if more than 20% of patients were lost to followup
or reasons for loss to follow-up differed between treatment
arms.