I'm Marian Sullivan from the National Blood Data Resource Center. I was sitting back there trying to decide which of my data to defend first here today, and I decided to speak for a couple of minutes about our year 2000 projection.
The projection, which has been quickly flashed on the screen a couple of times here today, could benefit from being put in better perspective, I think. Without the benefit of the other slides that led up to its presentation at the advisory committee meeting, it's a little bit difficult.
The projection resulted from an 18 month data collection and analysis process which involved 2,400 U.S. hospitals and blood center participants. As a result of this 1998 nationwide blood collection and utilization survey, the NBDRC and Westat produced national estimates for blood collections and transfusions in 1997.
These data were compared primarily with data from the Center for Blood Research -- which had been collected by the Center for Blood Research for 1994, the last year for which national data were collected prior to our survey.
However, we have also conducted an analysis of historical trends going back well into the 1980s. Considerable fluctuations are evident over these years. The year 2000 projection graph which you say today illustrates the trends in supply and demand for the most recent and most relevant period based on the 1994 and 1997 data.
The supply declined by 4 percent, or 1.3 percent per year, in this period. If I had my slides with me today, you could see that if we plot whole blood collections back to 1989 through 1997, the overall decline is 11 percent, or 1.4 percent per year, from 14.2 million to the 1997 figure, 12.6 million.
In fact, the slide which you did see today actually extrapolates the available supply rather than total whole blood collections. And this has somewhat softened the negative slope which you might have seen. And that's due to the fact that we have seen, during this period, a significant decrease in the test loss percentage which has softened the slope if we plot available supply, and that has been taken into account in our projection.
Regarding transfusion demand, the extrapolation which you saw illustrates a 3.7 percent increase in transfusion -- units transfused between 1994 and 1997, or 1.2 percent per year, which is not statistically significant.
In fact, if I had chosen to plot allogeneic, meaning community units transfused, you would see an increase in transfusions of 7.1 percent, which is significant. But the projection actually included all types of donated units transfused.
In fact, if you can once again imagine my absent slide showing historical trends back to the early '80s, what you see is that annual transfused units have actually leveled off since the early '90s. And prior to that, there was a very steep increase in the early '80s followed by a decline that began about 1986.
We do not believe that we have overstated this issue in our year 2000 projection. The assumptions we made were based on the most recent trends in collections and transfusions.
In fact, after I presented these data at the advisory committee meeting last month, a number of committee members, some of the speakers and some others closely involved in blood banking commented and seemed to agree that I had actually understated the problem.
And if, in fact, we had included other factors and prepared a more complex model, other factors such as the population increase and the redistribution of the population, as well as blood group availability -- if we had factored these things into our model, then the projection would have only been strengthened.
CHAIRMAN BROWN: Thank you very much, Marian, for a well tempered riposte to the criticisms.
I think -- Ray, is it about this? Because I was going to suggest that all of the people who have made public presentations stand ready to answer questions when this aspect reappears, which it will, almost immediately, if that's okay.
Marian, you'll probably be recalled to the stand, okay?
That concludes the public hearing part of our day and we now enter into deliberations, which is always the most amusing part of each day.