Systematic review on potential brain dead donor estimations and conversion rates to actually realized organ donations.

Introduction: Accurate estimations of potential organ donors (POTDs) are required to improve transplant systems. This systematic review analyses current studies on national estimations of potential donors for transplantation as well as the practical and policy implications of detected differences.

Method: A systematic review of literature published between 01.01.2010 and 01.04.2020 in PubMed was conducted. Data was extracted into a self-developed matrix, and further data retrieved on national population sizes, waiting lists and transplant activities.

Results: Six studies were included. Investigated populations, underlying data collections and eligibility criteria for POTDs varied widely. Estimated POTDs per million population (p.m.p.) ranged from 25.8 to 333.6, conversion rates from 3.2% to 47.5% leading to 41.2 to 86.4 transplanted organs p.m.p.. Patients on the waiting lists varied from 66.7 to 338.9 p.m.p., defining gaps between organ supply and demand in countries. Not all studies adhered to the definitions and processes of the critical pathway for deceased donation which is the latest international consensus statement on deceased organ donation.

Conclusion: Differences in estimated POTDs and differences in supply and demand of donor organs between countries cannot be satisfactorily explained yet due to an obvious lack of evidence, consistent methodology, international consensus and robust underlying datasets. Future studies should be based on robust underlying data sets and aim for potential donor estimations that allow national comparisons due to the adherence to the international consensus on definitions, processes and methodology.