ETHICS: The trial was approved by the South West–Central Bristol Research Ethics Committee, and trial oversight was provided by an independent trial steering committee and an independent data and safety monitoring committee. The study was conducted in accordance with the recommendations for physicians involved in research on human subjects adopted by the 18th World Medical Assembly, Helsinki 1964 and later revisions.
CONSENT: Written informed consent was obtained from all participants
AVAILABILITY OF DATA AND MATERIAL: The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Also, codes of STATA and R used in this study are available in Mendeley Data, V1, http://dx.doi.org/10.17632/j8fmdwd4jp.5.
CONFLICTS OF INTEREST/COMPETING INTERESTS: The authors declare they have no conflicts of interest.
FUNDING: This study was funded by the National Institute for Health Research (NIHR HTA) Programme (EVRA, project number 11/129/197).
AUTHORS CONTRIBUTION: All authors contributed to the study conception design and analysis, and read and approved the final manuscript.
ACKNOWLEDGEMENTS: We are grateful to the EVRA trial members for the availability of the data: Manjit S. Gohel, MD, Cambridge University Hospitals NHS Foundation Trust, United Kingdom, Jocelyn Mora, MSc, Francine Heatley, BSc, Alun H. Davies, DSc, Department of Surgery and Cancer, Imperial College London, United Kingdom; Matyas Szigeti, MSc, Jane Warwick, PhD, Imperial Clinical Trials Unit, School of Public Health, Imperial College London, United Kingdom; Andrew Bradbury, MD, University of Birmingham, United Kingdom; Richard Bulbulia, MD, Keith R. Poskitt, MD, Gloucestershire Hospitals National Health Service Foundation Trust, United Kingdom; Nicky Cullum, PhD, University of Manchester & Manchester University National Health Service Foundation Trust, United Kingdom; Isaac Nyamekye, MD, Worcestershire Acute Hospitals National Health Service Trust, United Kingdom; Sophie Renton, MS, North West London Hospitals National Health Service Trust, United Kingdom.
ADDITIONAL CONTRIBUTION: We thank the patient focus group who helped ascertain the importance of the EVRA research question, identify the most important outcome measures, and confirm the acceptability of trial interventions and follow-up protocols. As the Early Venous Reflux Ablation Trial Group, we thank the National Health Service centers and participating principal investigators and their colleagues for recruiting and monitoring trial participants: Addenbrooke’s Hospital: Manjit Gohel, MD, D. Read, P. Hayes, S. Hargreaves, K. Dhillon, M. Anwar, A. Liddle, and H. Brown; Bradford Royal Infirmary, Bradford: K. Mercer, F. Gill, A. Liu, W. Jepson, A. Wormwell, H. Rafferty, and K. Storton. Charing Cross & St Mary’s Hospitals, London: A.H. Davies, K. Dhillon, R. Kaur, E. Solomon, K. Sritharan, R. Velineni, C. S. Lim, A. Busuttil, R. Bootun, C. Bicknell, M. Jenkins, T. Lane, and E. Serjeant. Cheltenham General Hospital: K. Poskitt, R. Bulbulia, J. Waldron, G. Wolfrey, F. Slim, C. Davies, L. Emerson, M. Grasty, M. Whyman, C. Wakeley, A. Cooper, J. Clapp, N. Hogg, J. Howard, J. Dyer, S. Lyes, D. Teemul, K. Harvey, M. Pride, A. Kindon, H. Price, L. Flemming, G. Birch, H. Holmes, and J. Weston. Cumberland Infirmary: T. Joseph, R. Eiffel, T. Ojimba, T. Wilson, A. Hodgson, L. Robinson, J. Todhunter, D. Heagarty, A. Mckeane, and R. McCarthy. Derriford Hospital, Plymouth: J. Barwell, C. Northcott, A. Elstone, and C. West. Frimley Park Hospital: P. Chong, D. Gerrard, A. Croucher, S. Levy, C. Martin, and T. Craig. Hull Royal Infirmary: D. Carradice, A. Firth, E. Clarke, A. Oswald, J. Sinclair, I. Chetter, J. El-Sheikha, S. Nandhra, C. Leung, and J. Hatfield. Leeds General Infirmary: J. Scott, N. Dewhirst, J. Woods, D. Russell, R. Darwood, M. Troxler, J. Thackeray, D. Bell, D. Watson, L. Williamson, and M. Todd. Musgrove Park Hospital, Taunton: J. Coulston, P. Eyers, K. Darvall, I. Hunter, A. Stewart, A. Moss, J. Rewbury, C. Adams, L. Vickery, L. Foote, H. Durman, F. Venn, P. Hill, K. James, F. Luxton, D. Greenwell, K. Roberts, S. Mitchell, M. Tate, and H. Mills. New Cross Hospital, Wolverhampton: A. Garnham, D. McIntosh, M. Green, K. Collins, J. Rankin, P. Poulton, V. Isgar, and S. Hobbs. Northwick Park Hospital, Harrow: S. Renton, K. Dhillon, M. Trivedi, M. Kafeza, S. Parsapour, H. Moore, M. Najem, S. Connarty, H. Albon, C. Lloyd, J. Trant, and S. Chhabra. Queen Elizabeth Hospital, Birmingham: R. Vohra, J. McCormack, J. Marshall, V. Hardy, R. Rogoveanu, W. Goff, and D. Gardiner. Russells Hall Hospital, Dudley: A. Garnham, R. Gidda, S. Merotra, S. Shiralkar, A. Jayatunga, R. Pathak, A. Rehman, K. Randhawa, J. Lewis, S. Fullwood, S. Jennings, S. Cole, and M. Wall.Salisbury District Hospital: C. Ranaboldo, S. Hulin, C. Clarke, R. Fennelly, R. Cooper, R. Boyes, C. Draper, L. Harris, and D. Mead. Solihull Hospital (part of the University Hospitals Birmingham National Health System Foundation Trust): A. Bradbury, L. Kelly, G. Bate, H. Davies, M. Popplewell, M. Claridge, M. Gannon, H. Khaira, M. Scriven, T. Wilmink, D. Adam, and H. Nasr. Northern General Hospital, Sheffield: D. Dodd, S. Nawaz, J. Humphreys, M. Barnes, J. Sorrell, D. Swift, P. Phillips, H. Trender, N. Fenwick, H. Newell, and C. Mason. Royal Bournemouth General Hospital: D. Rittoo, S. Baker, R. Mitchell, S. Andrews, S. Williams, J. Stephenson, and L. Vamplew. Worcester Royal Hospital: I. Nyamekye, S. Holloway, W. Hayes, J. Day, C. Clayton, and D. Harding. York Hospital: A. Thompson, A. Gibson, Z. Murphy, T. Smith, and J. Whitwell. We thank members of our 2 oversight committees, the Trial Steering Committee (Professor Julie Brittenden [Chair]; Miss Rebecca Jane Winterborn [Consultant Vascular Surgeon]; Professor Andrea Nelson [Head of School and Professor of Wound Healing]; Dr Richard Haynes [Research Fellow and Honorary Consultant Nephrologist] and Mr Bruce Ley-Greaves [lay member] who provided invaluable input and advice as the independent lay member over the course of the study) and the Data Monitoring Committee (Professor Gerard Stansby [Chair, Professor of Vascular Surgery]; Professor Frank Smith [Professor of Vascular Surgery & Surgical Education]; Professor Marcus Flather [Professor of Medicine - Clinical Trials]; Dr Ian Nunney [Medical Statistician]) for their support and guidance. There was no financial compensation for these contributions.