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"The donors were randomised in this trial but the recipients were not."
The issue is one of blinding, not one of randomisation—the transplant coordinators providing care for organ donation were separate from the randomization process, so the recipients were allocated to donors independently of which groups donors were allocated to. Therefore the recipients were randomised too. (You can think of it as applying the randomisation to the groups consisting of donor and the recipients of that donor.)
The issue is that the team caring for the recipient was not blinded as to whether or not the donor had received a dopamine infusion, because this information was on the necrokidney report.
The lack of blinding could have caused these teams to subconsciously avoid dialysis in the recipients known to have organs subjected to the dopamine infusion, affecting the primary endpoint. To mitigate this, as shown in Table 4 of the article, an analysis was performed that established a dose-response relationship, showing that more dopamine (a longer infusion) resulted in fewer dialysis sessions. This was important because "the transplantation centres were unaware of the timing of the dopamine infusion in the donors."
No competing interests
19 September 2009
Rupert A Millard
College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT