One of the most important questions for patients on the waiting list is when will they get their kidney transplant. The Swiss transplant allocation algorithm relies predominantly on a ranking system based on points acquired by the patient due to waiting time, HLA match and cPRA scores. The allocation system provides for each organ offer a ranking of the listed patients.Methods
We calculated the potential future time point of transplantation for the individual patient based on his/her previous allocation history and ranking. All 198 patients who received a deceased donor kidney transplant at our hospital between Jan 2015 and Dec 2016 were analyzed, excluding those with combined organ transplants, pediatric and EBV-negative recipients. A regression analysis of date of organ offer and ranking score was computed for each individual patient. Based on this regression we calculated the predicted time point when the patient would be ranked on position one for the organ offer.Results
Altogether 107 patients were included in the final analysis. The allocation history and progression of ranking showed 4 different patterns. (a) Blood-group 0 cPRA-negative patients showed a steady and progressive advancement on the waiting list based on their waiting time which allowed an approximate prediction of their transplant date. (b) Highly immunized patients showed a very heterogeneous pattern that allowed no prediction of the potential time point of transplantation. For patients with blood groups A, B or AB the allocation pattern reflected (c) the priority rule for blood group preference as well as (d) the uneven distribution of blood groups in the Swiss population with a very low actual number of B and AB donors.Conclusion
Due to the multitude of additional factors impacting the actual ranking and transplant time point, in particular degree of sensitization, matching and number of donors per blood group a robust prediction is only possible for a small group of patients on the waiting list. However, the analysis of the ranking history shows the fairness of the allocation algorithm and the progress over time can be explained to the patient - which is highly valuable and appreciated by the individual patient waiting for their 'magic phone call'.