Transplant Statistics: Annual Report

Data Highlights
Kidney Data

Data concerning patients who have been placed on the waiting list for or who have received a kidney transplant can be found in Table 6.1 through 6.8. These data exclude patients who are placed on the waiting list for or who have received simultaneous pancreas and kidney transplants.

Kidney Waiting List Characteristics

Characteristics of patients on the kidney transplant waiting list can be found in Index 6.1.

The kidney waiting list increased from 19,046 in 1991 to 47,831 in 2000. There was a 9% increase between 1999 and 2000 alone. Growth was especially notable for older transplant candidate categories. The number of waiting list patients aged 50 and older also increased from 5,697 (30%) in 1991 to 23,631 (49%) in 2000. During this same period, the percentage of those aged 65 and older increased from 4% to 11%. Non-White waiting list patients constituted 44% of the kidney waiting list in 2000, compared with 38% in 1991. Between 1991 and 2000, the percentage of Hispanic patients on the waiting list steadily increased from 9% to 14%.

Kidney Waiting List Outcomes

Kidney times to transplant can also be found in Table 6.2. See Technical Notes for a discussion of methods for calculating time to transplant, which differs from the waiting time statistics used in previous Annual Reports. Data on death rates for the kidney waiting list can be found in Index 6.3.

Times to transplant for kidney transplantation have also increased over the last 10 years. At the end of 1991, 50% of waiting list patients had been on the waiting list for less than one year. By the end of 2000, however, this group accounted for only 38% of the waiting list (Table 6.1). Since 1991, median times to transplant have approximately doubled for each racial and ethnic group. Among patients listed in 1996, the median time to transplantation was 1,557 days for Black patients, 1,225 days for Asians, and 668 days for White patients. For Hispanics and non-Hispanics, waiting times were 1,137 days and 860 days, respectively. Median time to transplant for females listed in 1997 was 1,032 days compared with 881 days for males. In addition, for patients listed in 1997 with blood types A and AB, times to transplant were, at most, half as long as times for patients with blood types O and B. To illustrate, median times to transplantation were 1,248 days for blood type O and 1,501 days for blood type B but only 592 days for blood type A and 350 days for blood type AB.

Waiting list mortality has not improved with time. The death rate per 1,000 patient years increased from 55.4 in 1991 to 61.4 in 2000. Among adults, death rates are higher for older registrants. In 2000, waiting list patients aged 18 to 34 had an ADR of 30.3 compared with 49.2 for waiting list patients aged 35 to 49, 73.9 for those aged 50 to 64, and 101.0 for patients 65 and older. Over the last 10 years, White patients had death rates consistently above the rates for all other racial or ethnic groups. In 2000, the ADR for White waiting list patients was 66.8 compared with 56.9 for Black patients, 40.2 for Asian, and 48.7 for Hispanic waiting list patients. The ADR for male and female waiting list patients in 2000 were 59.5 and 64.0, respectively. These death rates do not include deaths that occurred after removal from the waiting list.

Kidney Transplant Recipient Characteristics

Data on kidney transplant recipient characteristics can be found in Index 6.4.

Kidney transplants performed in the year 2000 numbered 13,372 compared with 9,674 in 1991. Of the kidney transplants performed in 2000, 8,079 (60%) were from cadaveric donors and 5,293 (40%) were from living donors, as exhibited in Figure 13. Among cadaveric donor kidney recipients, 1,302 (16%) were between the ages of 18 and 34, 2,954 (37%) were between 50 and 64, and 2,677 (33%) were between 35 and 49. Among these recipients, 5,228 (65%) were White, 2,317 (29%) were Black, and 376 (5%) were Asian. Finally, 971 (12%) were Hispanic; 3,195 (40%) were female (Index 6.4). The number of cadaveric donor kidney transplant recipients aged 65 years or older increased from 315 (4%) in 1991 to 864 (11%) in 2000. Eighty-one percent of cadaveric kidney recipients had PRA values between 0% and 19%, while 3% had PRA values of 80% or greater. The percentage of cadaveric donor kidney recipients with a zero human leukocyte antigen (HLA) mismatch increased from 7% in 1991 to over 16% in 2000.

Among living donor kidney recipients, 1,230 (23%) were between the ages of 18 and 34, 1,880 (36%) were between 35 and 49, and 1,509 (29%) were between 50 and 64. Among these recipients, 4,270 (81%) were White, 729 (14%) were Black, and 175 (3%) were Asian; 586 (11%) were Hispanic. Finally, 2,236 (42%) were female. The number of living donor kidney transplant recipients aged 65 years or older increased from 23 (1%) in 1991 to 336 (6%) in 2000. Eighty-two percent of living donor recipients had PRA values between 0% and 19%, while 1% had PRA values of 80% or greater. Among living donor kidney recipients, those with a zero HLA mismatch decreased from 23% in 1991 to 10% in 2000, while recipients with an HLA mismatch level of four or higher increased from 9% to 27% during the same time period. This may be due, in part, to the increased number of living unrelated donor transplants and to advances in the favorable results that can be achieved despite the use of less well-matched living donor kidneys.

Cadaveric Donor Kidney Graft and Patient Survival

Data on cadaveric kidney donor graft survival rates can be found in Table 6.6. Data on cadaveric kidney donor patient survival rates can be found in Table 6.7.

Recent overall one-year and five-year cadaveric kidney graft survival rates were 89% and 61%, respectively. One- and five-year cadaveric kidney transplant graft survival was comparable for women (89% and 62%) and men (89% and 61%). Among adult recipients, one- and five-year cadaveric graft survival was best (92% and 64%) for recipients between the ages of 35 and 49 years and least (84% and 50%) for those over age 65.
  
There was a negative relationship between the number of HLA mismatches among donors and recipients and five-year cadaveric kidney graft survival. Six antigen mismatched kidneys had a five-year survival of 55%, whereas zero antigen mismatched kidneys had a five-year survival of 68%. In contrast to analyses performed in previous years, one-year graft survival was surprisingly similar for zero antigen mismatched cadaveric donor kidneys and other well-matched cadaveric kidney grafts. Kidneys from cadaveric donors between the ages of 18 and 34 fared best (92% survival at one year) following transplantation while kidneys from cadaveric donors between the ages of 11 and 17 years showed 68% survival five years following transplantation. One-year (81%) and five-year (41%) survival was poorest for cadaveric kidneys from donors of age 65 years or older.

PRA continues to be an important predictor of outcome for cadaveric kidney transplantation. One- and five-year transplant survival was better (90% and 62%) for recipients with PRA values between 0% and 19%, whereas survival was poorest (82% and 51%) for those with PRA values of 80% or greater.

Asian recipients had the best one- and five-year cadaveric kidney graft survival (91% and 73%), followed by Whites (90% and 64%) and Blacks (88% and 52%). Similarly, Hispanics had better one- and five-year cadaveric graft survival (92% and 67%) than did non-Hispanics (89% and 60%).

Recent overall one-year and five-year cadaveric kidney recipient survival rates were 95% and 81%, respectively. Five-year adult patient survival was best for recipients between the ages of 18 and 34 (92%) and worst for patients 65 years of age or older (59%). Asian cadaveric donor kidney transplant recipients, with a five-year survival rate of 90%, had better survival than did Blacks, at 81%, and Whites, at 81%. Similarly, Hispanics had a better five-year cadaveric donor graft survival rate, at 85%, than did non-Hispanics, at 81%. Five-year diabetic patient survival was 71%.

Living Donor Kidney Graft and Patient Survival

Data on living kidney donor graft survival rates can be found in Table 6.6. Data on living kidney donor patient survival rates can be found in Table 6.7.

Recent overall one-year and five-year living donor kidney graft survival rates were 95% and 76%, respectively. One- and five-year living kidney graft survival was 94% and 77% for women and 96% and 75% for men.

Differences in five-year graft survival, based upon the degree of HLA mismatch, were striking and are shown in Figure 14. The five-year graft survival for six antigen mismatched living donor kidney transplants was 58% whereas zero antigen mismatched living donor kidney transplants had a five-year survival of 87%. Kidneys from living donors between the ages of 18 and 64 years were similar at one-year posttransplantation. One-year (89%) and five-year (61%) living donor renal graft survival was worst for kidneys from donors of age 65 years or older.

Asian living donor kidney transplant recipients had the best one- and five-year living donor graft survival (96% and 86%) followed by Whites (95% and 78%) and Blacks (93% and 62%). Hispanics had better one- and five-year living donor graft survival (95% and 80%) than did non-Hispanics (95% and 75%).

Recent overall one-year and five-year living donor kidney recipient survival rates were 98% and 91%, respectively. Five-year adult patient survival was highest for recipients between the ages of 18 and 34 (95%) and for women (92%); it was worst for patients 65 years of age or older (71%) and for men (89%). Asian living donor kidney transplant recipients with one- and five-year survival rates of 98% and 94% had better survival than did Whites (98% and 91%) and Blacks (97% and 89%). Hispanics had better one- and five-year living donor graft survival (99% and 94%) than did non-Hispanics (98% and 90%). One- and five-year diabetic patient survival was 96% and 84%, respectively.