Decision tables and rule engines in organ allocation systems for optimal transparency and flexibility

A Systematic Review of Kidney Transplantation Decision Modelling Studies

BACKGROUND

Genome-based precision medicine strategies promise to minimize premature graft loss after renal transplantation, through precision approaches to immune compatibility matching between kidney donors and recipients. The potential adoption of this technology calls for important changes to clinical management processes and allocation policy. Such potential policy change decisions may be supported by decision models from health economics, comparative effectiveness research and operations management.

OBJECTIVE

We used a systematic approach to identify and extract information about models published in the kidney transplantation literature and provide an overview of the status of our collective model-based knowledge about the kidney transplant process.

METHODS

Database searches were conducted in MEDLINE, Embase, Web of Science and other sources, for reviews and primary studies. We reviewed all English-language papers that presented a model that could be a tool to support decision making in kidney transplantation. Data were extracted on the clinical context and modelling methods used.

RESULTS

A total of 144 studies were included, most of which focused on a single component of the transplantation process, such as immunosuppressive therapy or donor-recipient matching and organ allocation policies. Pre- and post-transplant processes have rarely been modelled together.

CONCLUSION

A whole-disease modelling approach is preferred to inform precision medicine policy, given its potential upstream implementation in the treatment pathway. This requires consideration of pre- and post-transplant natural history, risk factors for allograft dysfunction and failure, and other post-transplant outcomes. Our call is for greater collaboration across disciplines and whole-disease modelling approaches to more accurately simulate complex policy decisions about the integration of precision medicine tools in kidney transplantation.

[Distribution of livers from deceased donors : current allocation rules and algorithms]

Eurotransplant is responsible for the allocation of organs from deceased donors in Germany. The guidelines governing this allocation process have been developed and are continuously updated by the German Medical Association and are based on urgency and outcome of the planned transplantation. The allocation sequence for donor livers is based on the model of end-stage liver disease (MELD) score, which is calculated using three laboratory values, bilirubin, creatinine and the international normalized ratio (INR) and allows an objective and transparent evaluation of the urgency of the transplantation. For patients with liver diseases where the MELD score does not allow an estimation of the urgency of the transplantation, special rules apply. The international cooperation among the Eurotransplant member countries especially increases the probability of finding a suitable donor organ in time for highly urgent patients and patients with special difficulties in matching characteristics.

Waitlist characteristics of patients at a single-center intestinal and multivisceral transplant program

Intestinal transplantation (ITX) can be a successful treatment for patients with irreversible intestinal failure and associated severe complications. Because of long waiting periods and organ shortages, the precise identification of eligible patients and their early referral to centers that perform ITX is important. We retrospectively analyzed all patients who were referred to our center between 2000 and 2011 concerning their referral criteria, waitlist characteristics, and outcome. A total of 87 patients (47 male patients, 40 female patients; median age 39.8 ± 13.4 years) were referred to our center. All patients presented with intestinal failure caused by short bowel syndrome or motility disorders. About 80.5% of patients were evaluated for isolated ITX, modified multivisceral (mMVTX), or multivisceral transplantation (MVTX). About 56.3% were listed at EUROTRANSPLANT, 33.3% suffered from severe secondary organ failure requiring MVTX, and 34.5% were transplanted. 14.3% (all MVTX-candidates) died on the waitlist as a result of infectious complications. The high proportion of MVTX candidates underlines the need for early referral to specialized centers. MVTX-candidates have a high waitlist mortality for different reasons. However, the current allocation policy for MVTX does not mirror the severity of disease and may therefore contribute to high waitlist mortality.