Geographic inequity in access to livers for transplantation

Abstract

Background: Liver transplantation offers life-saving therapy for patients with decompensated liver disease or T2 hepatocellular carcinomas. In the United States, deceased donor livers are primarily allocated by Model for End-Stage Liver Disease (MELD) score within each of the country's more than 50 donation service areas (DSAs). Variation in DSA size, population, and organ availability have engendered concern that unequal access to deceased donor livers across DSAs contributes to geographic variability in outcome.

Methods: To determine the extent to which DSA variability in organ availability correlated with combined waitlist and posttransplant mortality, we analyzed retrospectively national waitlist and posttransplant data for a 7-year period after implementation of the current MELD-based allocation system.

Results: Marked variation among DSAs was evident in death rate (3.3-fold), transplant rate (20-fold), and mean transplant MELD (>10 points). Death rate correlated with organ availability was assessed by transplant rate and transplant MELD. DSAs with low organ availability included the country's largest cities, had more new listings per capita, larger waitlists, more transplant centers per DSA, and a higher proportion of black and Asian patients. DSAs of organ shortage were also characterized by more frequent dual listing at another transplant center, more living donor liver transplants, and increased average length of the transplant admission.

Conclusions: Geographic differences in deceased donor organ availability contribute to variation in overall death rate of liver transplant patients, shape the clinical practice of transplant, and influence the resources consumed per transplant. Geographic variation in organ access results primarily from rates of listing rather than donation. Our findings highlight the need to restructure organ distribution areas to achieve equal access to deceased donor livers for transplantation in the United States.

Figure 1

(a and b) Graphs are plotted on a log scale. Death rate and transplant rate are expressed in events per 100 patient years and per 100 patient months, respectively. Trend lines were determined by weighted linear regression, and P values were calculated using an F-test. (a) Correlation of death rate and transplant rate, by region. (b) Correlation of death rate and transplant rate, by donation service area (DSA). (c) Correlation of death rate with Model for End-Stage Liver Disease (MELD) at transplant, by region. (d) Correlation of death rate with MELD at transplant, by DSA.

Figure 2

Relative organ availability by United Network of Organ Sharing region (a) and donation service area (DSA) (b) stratified by corrected Model for End-Stage Liver Disease (MELD) at transplant/censoring and quartile of corrected MELD at transplant, increasing from quartile 1 to 4. DSAs not transplanting during the full study period are marked (stippled) as are export-only DSAs (white). (a) Relative organ availability, by region. (b) Relative organ availability, by DSA.

Figure 3

Correlation of relative organ availability with posttransplant hospital length of stay and regional review board (RRB) petitions for additional priority points. Mean hospital length of stay by region (a) and donation service area (DSA) (b) is plotted versus corrected Model for End-Stage Liver Disease (MELD) at transplant as a measure of relative organ availability. Length of stay (a and b) is expressed in days posttransplant. It does not include pretransplant days in the hospital if the patient was in house at the time of transplant. The mean number of RRB applications (c) and percent approvals (d) for additional MELD priority points for special exception cases is shown by region versus correct MELD at transplant. Application rate was calculated from the number of applications to the RRB (excluding hepatocellular carcinoma meeting standard criteria) per number of patients listed. This included all patients on the waitlist in the 48 analyzed DSAs of any MELD Score. Approval rate was calculated as the number of approvals per application. (a) Hospital length of stay and MELD at transplant, by region. (b) Hospital length of stay and MELD at transplant, by DSA. (c) RRB petitions and MELD at transplant. (d) RRB approval and MELD at transplant.