[Terra incognita of tissue donation: A systematic literature review analyzing institutional factors influencing the willingness to donate tissue].

Introduction: Partly because of a lack of governmental commitment in educational work, tissue donation is largely unknown in the German population, although it has an increasing relevance for patient care. Due to the progress in research, the shortage of donor tissues in Germany is constantly increasing and has to be compensated by imports. In contrast, nations such as the USA are self-sufficient in donor tissue and can even export it. Since not only individual but also institutional factors (e.g., legal framework, allocation principles and the organization of tissue donation) can lead to these national differences in donor rates, the present systematic literature review will investigate how these factors influence the willingness to donate tissue.

Methods: Relevant publications were systematically searched in seven databases. The search command consisted of English and German terms for the two search components "tissue donation" and "health care system". Papers published in English or German between 2004 and May 2021 and focusing on the analysis of institutional factors influencing the willingness to donate tissue post-mortem for transplantation were included (inclusion criteria); studies on blood and organ and living donation as well as publications not dealing with institutional factors influencing the willingness to donate tissue were excluded (exclusion criteria). In reporting, we followed the PRISMA 2020 statement.

Results: Of 1,398 hits, seven were finally included after screening. Many of the remaining studies focused on organ donation or non-institutional aspects of tissue donation. Only two studies considered the central population perspective. Furthermore, five publications originate from an Australian research group and focus on the international allocation of tissues. The results highlight the inadequate state of research and at the same time suggest that both tissue bank organization and allocation principles may influence the willingness to donate tissue. At the same time, the publications indicate that tissue donors are often not informed about a potential commercial use or an international allocation of tissues, which represents an ethical-legal conflict.

Conclusion: The results indicate that institutional factors may influence people's willingness to donate. In particular, the lack of societal awareness of the issue results in various areas of tension for which recommendations for action have been developed. In order to prevent a slump in tissue donations because of socially unacceptable practices, further population-based studies should explore the institutional framework conditions that society demands for tissue donation.