Transplant science, transplant politics , and public perception--the case of living-donor livers

 Liver transplants from living donors are on the increase in the U.S., so liver transplants are coming to more closely resemble kidney transplants.  Apparently that comes with some of the politics that I've witnessed involving kidney transplants. At least that's what the article below, by a very large and distinguished set of American authors, seems to be dealing with, in this critique of a paper published in a European journal. (It's unusual to see a question about scientific integrity highlighted in the title of an academic paper...). Apparently the title of the paper being criticized received news coverage unfavorable to transplantation, and not justified by the data being reported.

Emamaullee, J., Heimbach, J.K., Olthoff, K.M., Pomfret, E.A., Roberts, J.P., Selzner, N. and NALLDIG Consortium, 2022. Assessment of long‐term outcomes post living liver donation highlights the importance of scientific integrity when presenting transplant registry data. American Journal of Transplantation, online early,  First published: 30 March 2022 https://doi.org/10.1111/ajt.17045

"Abstract: Living donor liver transplantation has expanded in recent years, particularly in North America. As experience with this procedure has matured over the last 25 years, centers are increasingly faced with potential living donors who are more medically complex. As donors move through the evaluation process, completing the informed consent process continues to be challenged by a paucity of granular data demonstrating long-term outcomes and overall safety specifically in the otherwise ‘healthy’ living liver donor population. Two recently published studies examined long-term outcomes post-living liver donation using Korean registry data and reported similar results, with excellent overall survival when compared to appropriately matched controls. However, the authors of these studies were presented differently, with one reporting an alarmist view based on one aspect of a suboptimal analysis approach using an inappropriate comparator group. Herein, the North American Living Liver Donor Innovation Group (NALLDIG) consortium discusses these two studies and their potential impact on living liver donation in North America, ultimately highlighting the importance of scientific integrity in data presentation and dissemination when using transplant registry data."

"Recently, in the Journal of Hepatology, Choi and colleagues published a noteworthy study of long-term outcomes of Korean living liver donors, titled “Outcomes of living liver donors are worse than those of matched healthy controls.”

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"Although careful examination of long-term outcomes for living liver donors is essential, and the South Korean population is an excellent population in which to conduct these analyses given the relative frequency of living donor liver transplantation, the current study suffers from a serious design flaw which makes interpretation of the data very challenging, as highlighted in detail in the letter to the editor from the Toronto group.4 Indeed, the Control Group I “heathy population” is actually healthier than the living liver donors given that “the proportion of individuals with Charlson Comorbidity Index ≥1, diabetes, hypertension, or depression in the living liver donor group was higher than that in the matched healthy group (Control Group I).” They then use this heavily weighted (10:1 match) heathier group to demonstrate, unsurprisingly, a subtle but statistically worse outcome in the living liver donor group, hence the title of the paper. 

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"Unfortunately, both the manuscript title, “Outcomes of living liver donors are worse than those of matched healthy controls” and the lay summary, which is intended for the public at large are highly misleading, given this lack of a matched control group. This leads to confusion and uncertainty not only for those within the medical community but also for prior donors as well as for future potential living donors and their recipients. One may wonder whether these choices were made to drive the sensationalism of the media on this topic particularly in some European countries where practice of LDLT is no longer pursued for a variety of reasons including overall skepticism that the procedure is truly safe for living donors.

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"Journal editorial boards bear the responsibility of arranging high-quality, expert peer review. The dramatic increase in the volume of manuscripts submissions during COVID-19 pandemic has strained many editorial board members and reviewers, likely resulting in publication of studies of variable rigor.16 In parallel, careful assessment of statistical techniques and interpretation of analyses has become an integral part of the review process. Many journals now employ full-time statistical editors, which has enabled identification of serious flaws in experimental design including insufficient study power, missing data, or inappropriate use of statistical tests or models.17 Editors must also critically assess the power of a provocative manuscript title, as initially it may grab the reader's attention and can bias the reader's interpretation and impression. Journals also must be willing to publish studies even when results are disappointing and/or controversial. The transplant community should continue to carefully assess and respond to any work that may dampen enthusiasm for living donation or living donor liver transplantation."