The intricate relationship between evidence and clinical practice in kidney transplantation.

Clinical practice is supposed to be evidence-based but it always conveys underlying values, judgements, moral principles or axioms. We explore the evidence-based nature of clinical practice in the fast-changing field of kidney transplantation and its relationship with values in five different interventions: those well supported on evidence, focussed on the use of immunosuppressant drugs like cyclosporine, mycophenolate mofetil and tacrolimus, and the elective withdrawal of cyclosporine or steroids; disputable interventions where evidence, focussed on anti-lymphocyte antibodies, is strong but not strong enough to be applied on the majority of occasions; interventions not supported by randomised controlled trials with focus on primary treatment of vascular graft rejection and rescue treatment for acute graft rejection; interventions not widely applied despite strong evidence from sources other than randomised controlled trials, with focus on HLA-matched kidney transplants in cadaver donor and living donor transplants; and finally, a variety of interventions when evidence is lacking. Being aware of the factors influencing every clinical decision we can make the strength of evidence and the nature of the values underlying them explicit and we will find it easier to improve the process of transferring evidence into practice and openly face and acknowledge the values involved.