The importance of considering competing treatment affecting prognosis in the evaluation of therapy in trials: the example of renal transplantation in hemodialysis trials

Creative Commons License

Hazelbag C. M. , Peters S. A. E. , Blankestijn P. J. , Bots M. L. , CANAUD B., Davenport A., ...More

NEPHROLOGY DIALYSIS TRANSPLANTATION, vol.32, pp.31-39, 2017 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 32
  • Publication Date: 2017
  • Doi Number: 10.1093/ndt/gfw458
  • Page Numbers: pp.31-39


Background. During the follow-up in a randomized controlled trial (RCT), participants may receive additional (non-randomly allocated) treatment that affects the outcome. Typically such additional treatment is not taken into account in evaluation of the results. Two pivotal trials of the effects of hemodiafiltration (HDF) versus hemodialysis (HD) on mortality in patients with end-stage renal disease reported differing results. We set out to evaluate to what extent methods to take other treatments (i.e. renal transplantation) into account may explain the difference in findings between RCTs. This is illustrated using a clinical example of two RCTs estimating the effect of HDF versus HD on mortality.