The UNOS OPTN waiting list: 1988-1995.

On November 30, 1995, the combined waiting list contained 43,370 registrants, a 15.1% increase from the 37,684 registrations as of December 31, 1994. Kidney registrations accounted for the majority (70.9%) of registrations. The predominant characteristics of the registrants on the combined waiting list as of November 30, 1995 are as follows: 57.6% were male; 59.2% were White; 57% were between 18-49 years of age; 51.4% were of blood type 0; and 82% had no previous transplant. The majority of kidney registrants (68.1%) had a current PRA value of 0-19%. The number of new registrations increased 69.6% from 17,441 additions in 1988 to 29,402 in 1994. The waiting lists with the highest percentage increase in additions over this period were the lung waiting list, ranging from 125 additions in 1988 to 1,544 additions in 1994, and the liver waiting list, ranging from 2,140 additions in 1988 to 6,211 additions in 1994. Since 1992, additions to the kidney-pancreas waiting list ranged from 743 to 1,222, a 64.5% increase. Over the 1988-1992 time period, the rate of transplantation as a percentage of total waiting list registrations declined, decreasing approximately 1% per year. Meanwhile, the death rate per patient registered remained fairly stable, averaging 5.6% each year. The death rate for patients on the heart-lung waiting list decreased each year since 1989. Median waiting times increased annually for patients awaiting kidney and liver transplantation. For those registrants on the heart waiting list, median waiting times increased from 1988-1992, but decreased over the last 2 years. In contrast, lung registrants experienced decreasing median waiting times from 1988-1990, but median waiting times for lung registrants have increased since 1991. Patients awaiting heart-lung transplantation experienced the longest median waiting time in each year except 1993, when the median waiting time for kidney waiting list registrants surpassed that of heart-lung registrants. Patients awaiting liver transplantation experienced the shortest median waiting times each year except 1992. Of those patients added to the combined waiting list in 1993, patients with blood type O on the kidney, liver, heart, lung and heart-lung waiting lists had longer median waiting times than those with blood types A, B or AB. In general, patients having a previous transplant waited longer than those who had not had a previous transplant, with the exception of patients awaiting liver and pancreas transplantation. Females on the kidney, kidney-pancreas, liver, lung and heart-lung waiting lists experienced longer median waiting times than males. Median waiting times were shorter for females on the pancreas (278 vs 436 days) and heart (144 vs 240 days) waiting lists. Median waiting times were shortest for Whites registered on the kidney and lung waiting lists, for Hispanics on the liver list and for Asians on the heart and heart-lung waiting lists. Patients of ¿other¿ racial backgrounds experienced the shortest median waiting time on the kidney-pancreas waiting list. In general, pediatric patients experienced the shortest median waiting times of patients added to the waiting lists in 1993: Kidney and heart registrants less than one year of age had a median waiting time of 90 days and 47 days, respectively. Kidney-pancreas, lung and heart-lung registrants aged 1-5 years had a median waiting time of 81.5 days, 220 days, and 153 days, respectively. Conversely, older patients typically waited the longest for an organ transplant. Patients over 50 years of age experienced the longest median waiting times of patients registered on the kidney, kidney-pancreas, pancreas and heart waiting lists.