title: Allocation of treatment to patients when not all balancing factors are known to the co-ordinating centre.
abstract: The allocation of treatment to patients in a clinical trial while balancing for prognostic factors is usually done by a co-ordinating centre when all the factors are known. In a trial comparing two treatments of acute rejection of renal allografts some prognostic factors become available to the physician only at the moment of the diagnosis of the rejection. This diagnosis is often made out of office hours, whereas immediate start of treatment is essential. It is shown here that the co-ordinating centre is still able to control the allocation of patients to treatment groups if a small number of prognostic factors is known only to the physician.
mesh_terms: D002986:Clinical Trials as Topic / Q000379:methods*; D006084:Graft Rejection; D006801:Humans; D016030:Kidney Transplantation; D011379:Prognosis; D011897:Random Allocation; D012107:Research Design