Fig. 2

Trends over time for use of flow diagram and recruitment and retention rates. Control charts: for significant trends, the mean is shown as a red stippled line. The grey area marks the control limits. Red points outside the control limits indicate an unstable process and thereby a trend. a The use of adequate patient flow diagrams: control chart showing a significant increase in the use of adequate flow diagrams. Flow diagrams were deemed adequate when they reported the number of participants screened for eligibility, randomised and included in primary analysis for each trial arm. b Recruitment over time: control chart showing no significant trends for recruitment rate over time. We defined recruitment as the rate between number of randomised participants and participants screened for eligibility. c Retention over time: control chart showing no significant trends for retention rate over time. We defined retention as the rate between number of participants included in the primary analysis and of randomised participants