Pro: Patient and allograft survival remain the best metric to gauge successful liver transplantation.

Watch a video presentation of this article Watch the interview with the author The Scientific Registry of Transplant Recipients (SRTR), a Health Resources and Services Administration–sponsored federal database, has been releasing program-specific reports (PSRs) documenting the outcomes of solid organ transplant programs for more than two decades.1 Since its inception, patient and allograft survival following orthotopic liver transplantation (OLT) have formed the foundation for PSR performance assessment. PSR use has been implicated in the observation of continually improved outcomes among OLT recipients but may have contributed to a perception of risk aversion in donor and recipient selection.2, 3 In an attempt to increase donor utilization and reduce wait-list mortality, various modifications in PSR analyses have been proposed to create a more comprehensive transplant performance metric (CTPM).4, 5 Although the creation of a CTPM is a laudable goal, current data do not support behaviors of risk aversion within the OLT community (Fig. 1). In fact, the number of liver transplants performed in 2016 increased 10% from 2015 to an all-time high.1 Disease acuity has also steadily increased as reflected by the mean and median Model for End-Stage Liver Disease (MELD) score, as well as recipient age at OLT. Thus, the current recipient cohort reflects the greatest number of transplants being performed on a group with the highest mean and median MELD scores and largest component of recipients older than 65 years.1, 6 The introduction of additional, unvalidated metrics risks further behaviors that may deter donor use and recipient selection. The most frequently advocated is inclusion of wait-list mortality. Presently, transplant programs can execute their own philosophies regarding listing a patient for OLT without regard to performance metrics. The incorporation of wait-list mortality into PSR performance analyses would incentivize transplant programs to list only those patients who had a very high likelihood of receiving a transplant. Waiting lists would become much smaller and restrictive because patients who had clinical indications for OLT but do not qualify for placement in the upper, immediate tier for allocation would be warehoused while their disease progressed. Mortality in this group would markedly increase through two mechanisms: the denial of an opportunity to receive an extended donor criteria allograft, and the stipulation that progression of disease occurs in a manner that facilitates identification and listing by a program in a timeframe conducive to transplantation. Transplant rate is reported in the PSR and has been proposed as a determinant of program performance. The limitation in utilizing transplant rate as a performance metric is the wide variation in organ availability. Although a program may influence its observed transplant rate by expanding deceased-donor utilization and incorporation of living donation, the expected transplant rate is currently calculated from the expected wait time according to listing MELD derived from national data. Therefore, until adjustments are incorporated for local organ availability, the observed-to-expected ratio of transplant rate will be artificially deflated in regions of organ scarcity and inflated in regions with a low average MELD at OLT. As with wait-list mortality, a way to enhance the observed-to-expected ratio would be to defer listing until OLT was imminent; however, this would infer the same negative consequences as described earlier. Lastly, the PSR has been criticized for overlooking quality of life (QOL) after OLT and focusing solely on survival. The World Health Organization defines QOL as a state of complete physical, mental, and social well-being, not merely the absence of disease.7 Although this definition is all-encompassing, the subjectivity inherent to QOL impairs its inclusion within performance metrics. Indeed, an attempt to include QOL into present performance analyses would have the greatest potential for disruption because of a lack of validated questionnaires tailored to transplant recipients, inconsistency among transplant recipients to rehabilitation resources after OLT that can significantly impact QOL, and most importantly, an allocation system designed to prioritize OLT to the most ill candidates. Multiple reports demonstrate MELD at OLT does not correlate to posttransplant QOL.8, 9 Thus, even with the development of validated transplant QOL metrics, access to rehabilitation services would need to be standardized and allograft allocation within the United States fundamentally changed to afford valid comparisons. A change to a QOL-based liver allocation system would abandon many candidates currently awaiting OLT while incentivizing transplant programs to transplant relatively healthy patients with early disease who may have averted OLT with proper medical therapy. QOL is an integral component of a decision to offer a patient OLT, but it should remain within the purview of the transplant program and not be included as a performance metric. In conclusion, insufficient metrics currently exist to support a validated CTPM. Survival remains the most reliable metric, not only in the realm of transplant, but in other medical interventions as well. It is an objective, quantifiable metric that can be adjusted across institutions and is universally used in research and quality reporting. Survival is the most frequently referenced primary outcome in medical journals and is routinely used to assess the efficacy of novel chemotherapy drugs, to measure outcomes in other areas of solid organ transplantation, and to determine the effect of medications on survival in other chronic diseases. In a survey of transplant recipients asked to rank posttransplant outcomes that were most important to them, of 47 outcomes, graft function, rejection, and their own survival were among the top 5 selected.10 Survival-based PSRs have led the transplant community through a period of sustained growth resulting in expansion of OLT to recipients of increasingly higher age and physiological MELD. The development of a CTPM should remain a priority of the transplant community; however, the introduction of proven metrics is paramount because unvalidated metrics risk the gains we have made to date.