[1] University of Liverpool,Medicines for Children Clinical Trials Unit
[2] University of Edinburgh,Centre for Population Health Sciences
[3] Bristol Randomised Trials Collaboration Trials Unit,MRC North West Hub for Trials Methodology Research, Department of Biostatistics
[4] MRC Clinical Trials Unit at UCL,undefined
[5] London Hub for Trials Methodology Research,undefined
[6] Centre for Healthcare Randomised Trials (CHaRT),undefined
[7] University of Liverpool,undefined