Estimating the number of potential organ donors in the United States

Background: As the need for transplantable organs increases, waiting lists of patients become longer. We studied the size and composition of the national pool of brain-dead organ donors during a three-year period and, on the basis of these data, considered ways to increase the rate of donation.

Methods: We reviewed hospital medical records of deaths occurring in the intensive care unit from 1997 through 1999 in the service areas of 36 organ-procurement organizations to identify brain-dead potential organ donors. We examined data on characteristics of the potential donors, the processes of referral to organ-procurement organizations and of requesting donations, and the hospitals.

Results: We identified a total of 18,524 brain-dead potential organ donors during the study period. The predicted annual number of brain-dead potential organ donors is between 10,500 and 13,800. The overall consent rate (the number of families agreeing to donate divided by the number of families asked to donate) for 1997 through 1999 was 54 percent, and the overall conversion rate (the number of actual donors divided by the number of potential donors) was 42 percent. Hospitals with 150 or more beds were more likely than smaller hospitals to have potential donors and actual donors (P<0.001); 19 percent of hospitals accounted for 80 percent of all potential donors. Calculations of the number of donors per million persons in the general population did not correlate well with the performance of organ-procurement organizations as measured by the conversion rate.

Conclusions: Lack of consent to a request for donation was the primary cause of the gap between the number of potential donors and the number of actual donors. Since potential and actual donors are highly concentrated in larger hospitals, resources invested to improve the process of obtaining consent in larger hospitals should maximize the rate of organ recovery. The performance of organ-procurement organizations can be assessed objectively through the comparison of the number of actual donors with the number of potential donors in the given service area.