About 90 percent of the U.S. blood supply is collected by two suppliers— the American Red Cross and independent centers affiliated with ABC. Generally, suppliers collect, test, and process blood and sell it to health care providers. FDA is responsible for ensuring the safety of the U.S. blood supply, which it does by inspecting blood collection procedures and enforcing federal regulations. Although past monitoring efforts by industry and nonprofit groups have examined supply and demand trends for blood, current efforts are focused on providing daily monitoring of hospitals’ blood inventories. In the United States, about 8 million volunteers donate approximately 14 million units of whole blood each year. Sixty percent of the population is eligible to donate blood, but in any given year only about 5 percent of those who are eligible actually do so. Eighty percent of donors are repeat donors. A typical donor gives blood approximately 1.6 times a year, but donors may give 6 times a year, or every 8 weeks, which is the period the body needs to replenish red blood cells. The Red Cross and ABC each collect about 45 percent each of the nation’s blood supply, and roughly 10 percent is supplied by other independent blood centers, DOD, and hospitals that have their own blood banks. Most hospital transfusion services purchase blood and blood components under a contract with a local supplier which describes the price and quantity of blood to be delivered. Blood suppliers use resource-sharing programs to help suppliers in high-demand areas buy blood that is not needed by the supplier that collected it. Taken together, the Red Cross, ABC, and AABB’s National Blood Exchange moved about 1.4 million units of blood—over 10 percent of the nation’s supply—among suppliers in 2000. In addition, the Red Cross has a nationwide inventory control system to facilitate the movement of its surplus blood. Donated blood is tested for blood type (A, B, AB, and O) and Rh type (positive or negative). Donors with type O Rh negative blood are known as “universal donors,” since it can be given to patients of any blood type in an emergency. Donated blood is also screened for a number of diseases and other elements that could prevent its use. For example, blood is tested for red blood cell antibodies that may cause an adverse reaction in recipients and screened for hepatitis viruses B and C, human immunodeficiency viruses (HIV) 1 and 2, other viruses, and syphilis. Most U.S. blood products are now filtered to remove a class of cells known as leukocytes (white blood cells), which have been implicated in adverse transfusion reactions. Each unit of whole blood is separated into specialized components, or “products,” consisting of various types of blood cells, plasma, and special preparations of plasma. Health care facilities transfuse the resulting 26.5 million components into about 4.5 million patients per year. Red blood cells may be stored as a liquid for up to 42 days. Blood banks maintain a supply cushion to meet the uncertain demand for blood. This means that some blood is discarded; for example, from January through August 2001, about 2 percent of the blood supply expired without being transfused. Red blood cells can also be frozen and stored for later use. The military makes extensive use of frozen blood inventories to meet wartime contingencies, maintaining stocks of frozen type O units that can be transferred into most patients regardless of their blood types. However, because freezing and thawing blood is expensive and labor intensive, civilian blood centers maintain relatively small inventories of frozen blood, primarily of rare blood types. A new device approved by FDA in May 2001 may make frozen blood more useful in the future—it can extend the shelf life of thawed, previously frozen blood from 24 hours to 14 days. There are several ways for hospitals to reduce the amount of blood they use. For example, one large hospital we contacted was able to save $1 million and 10,000 units of blood over 8 years by promoting awareness of blood use among physicians and by improving how blood is ordered and used during surgeries. A recent study of blood use during neurosurgery at a large teaching hospital found that, because the hospital’s system for ordering blood had not kept pace with advancements in surgical techniques, physicians ordered 5.5 times more blood than was transfused during surgery. One multifaceted approach to blood conservation is known as bloodless surgery. This practice involves the use of pharmaceuticals that stimulate the production of red blood cells, surgical equipment that cleans and returns lost blood to the patient, and intravenous solutions that maintain blood volume. During a pilot study of bloodless surgery techniques, one hospital successfully used these techniques instead of blood transfusions for several hundred surgical patients. Federal Regulation of Blood The Public Health Service Act (PHSA) and the Federal Food Drug and Cosmetic Act form the basis of the Public Health Service’s authority, as enforced by FDA, to ensure the safety of blood that is collected and transfused in the United States. PHSA requires that all blood and blood components distributed in interstate commerce be licensed by FDA in order to ensure that the products are safe and effective. Under PHSA, FDA can recall blood and blood components that present an imminent or substantial hazard to public health. The licensing and regulatory standards set by FDA attempt to maintain a blood supply that is both adequate and safe. Blood suppliers routinely take safety precautions beyond those required by FDA. For example, although FDA has not required nucleic acid testing (NAT), a sophisticated test to detect HIV and hepatitis C virus (HCV), virtually all blood centers perform it. Similarly, FDA has not mandated universal leukoreduction, but most blood centers have adopted the practice. When suppliers violate regulations, FDA takes legal action to prevent further violations. These legal actions can result in the parties entering into consent decrees of permanent injunction to comply with all applicable blood safety rules. Several blood and plasma suppliers as well as manufacturers of blood testing supplies are currently under consent decrees for various violations. One of the most significant of these agreements now in force is with the Red Cross, which entered into a consent decree in 1993, after FDA discovered that the Red Cross had failed to follow its own standard operating procedures, had deficiencies in its quality control processes, and had committed other violations. FDA has no authority to determine the amount of blood that should be collected or to compel suppliers to make products available. However, FDA recognizes that an insufficient blood supply is a public health risk, and it can make certain recommendations within its authority under PHSA and the Federal Food, Drug and Cosmetic Act, as amended, related to the availability of blood during public health emergencies. In an emergency, FDA and other HHS agencies can give advice to blood banks on prioritizing the use of blood and facilitating the shipment of existing inventory to the areas affected. For example, after the September 11 attacks, FDA issued emergency guidelines to speed the delivery of blood to areas affected by the attacks. The guidelines allowed donated blood to be shipped to crisis areas before NAT was completed and to allow clinical staff who were not trained in all procedures to collect blood, in order to supplement the fully trained staff. FDA’s emergency guidelines were rescinded on September 14, 2001, upon recognition that blood supplies were more than adequate to address current needs. HHS also can purchase blood and blood components and make other arrangements to respond to threats to the safety and sufficiency of the blood supply. While periodic surveys of the blood supply have been conducted for years, no data on daily, weekly, or monthly national and regional blood collections or usages were readily available to federal officials or blood suppliers until 2000. NBDRC has conducted a biennial retrospective survey of blood suppliers since 1997, and others conducted similar periodic surveys before that. NBDRC’s latest comprehensive biennial survey of blood supply and usage measured all units collected and transfused in 1999. In periods between these biennial surveys, NBDRC conducts interim retrospective studies that measure the pace and number of collections. In addition, both the Red Cross and ABC have reported their annual collections from 1996 through 2001. Both the Red Cross and ABC have taken steps recently to improve the measurement of blood collections and inventories in their own centers. For example, the Red Cross recently introduced a large-scale, centralized inventory tracking system. This system monitors blood inventories and distribution daily across all Red Cross blood centers, enabling projections of demand and potential shortages using both daily data and historic blood usage patterns. Since March 2002, the independent blood centers affiliated with ABC have participated in a less comprehensive daily inventory reporting system. In November 1999, HHS made a commitment to improve the monitoring of the blood supply as part of its Blood Action Plan announced in 1998. As a first step, the HHS Office of the Assistant Secretary for Health and NHLBI contracted with NBDRC to provide monthly data on supply and demand trends using a statistically representative sample of 26 blood suppliers that account for about one-third of U.S. blood collections. Data from this survey in 2000 indicated that the blood inventory was stable and that blood banks were absorbing the impact of the first vCJD donor deferral better than initially expected. NHLBI terminated the NBDRC contract, and OPHS assumed support for the NBDRC data collection effort through the end of 2001. NBDRC has continued this data collection effort without public funding. Partly to compensate for the loss of the NBDRC data, OPHS introduced its own early warning, or sentinel, system in August 2001. The system is designed to detect blood shortages that may adversely affect patient care and analyze demand trends at transfusion centers and hospitals nationwide. OPHS collects daily blood inventory and use data from 26 hospitals and three transfusion centers that account for about 10 percent of the national blood inventory. Although the hospital sample is not statistically representative, it includes both small and large hospitals in different geographic regions of the United States meant to serve as indicators of impending blood shortages.