UDC Information for People with Bleeding Disorders

Mother and child with counselor

The Universal Data Collection (UDC) system was created because people with bleeding disorders demonstrated to Congress the need for more information in order to improve care for those affected. The project was carried out with the help of federally funded hemophilia treatment centers (HTCs) in the United States. During the project’s operation from 1998-2011 more than 27,000 people with bleeding disorders participated in UDC. It is estimated that more than 80% of all people with hemophilia were cared for at HTCs during that time. A new monitoring initiative, Community Counts, builds on the work of the UDC and continues data collection in collaboration with the HTCs. In addition to data collection activities, other research studies are being conducted to define and determine the causes and complications of hemophilia.

UDC Participation

The UDC system was open to people of all ages with bleeding disorders, including babies. People with a bleeding disorder who received care at a federally funded HTC were able to enroll.


Federal privacy laws require your HTC and CDC to protect your information. You will be assigned a unique identification (ID) number. Your privacy is protected by using this number on all forms and blood samples sent to CDC. Only your HTC can match your number to your name. Your ID number will never be given to hospital, insurance company, employer, or school, no matter what. Not even a court of law can make your HTC give out this information. CDC will never receive your name and will not be able to link you to your data in any way.

Healthcare provider checking range of motion

Important Findings

This study is looking at trends and changes over time, so the analyses are ongoing. A few of the findings so far are:

  • Youth with hemophilia are just as likely as youth among the general population to be overweight.
  • Youth with hemophilia who are overweight are more likely to have decreased joint mobility than those who are not overweight.
  • Joint infections are a rare complication of hemophilia, but they are more common among people with hemophilia than among those without the condition. Infections happen mainly in problem joints that bleed frequently or have undergone joint surgery.
  • No new infections of hepatitis A, hepatitis B, hepatitis C, or HIV have been linked to blood products used to treat bleeding disorders.
  • Among deaths of people with bleeding disorders reported to CDC during the period 1997–2007, the most common causes were related to HIV infection (19%) and liver disease (22%) probably related to hepatitis C infection. Both of these infections could be transmitted by hemophilia treatment products before 1986. Hemophilia-related (bleeding) causes of death were less common (12%).
  • The most common sites of bleeding among babies with hemophilia are the circumcision site and the head. Bleeding inside the head (intracranial hemorrhage) is a very serious complication and can result in long-term effects such as seizures and learning disabilities.
  • Intracranial hemorrhage (ICH) is a bleed inside the skull. The most significant risk factors for an ICH are (1) having an inhibitor (2) prior ICH (3) severe hemophilia and (4) reported head trauma. Consistent use of preventive medication can reduce the likelihood that an ICH will occur.
  • The rate of new inhibitors (antibodies to treatment products) among previously treated patients with hemophilia is very low. However, more study is needed to determine why they occur because an inhibitor makes treating hemophilia more complicated and expensive.
  • Overweight and obesity accelerates joint mobility loss in weight-bearing joints, particularly among those with severe hemophilia.
  • Youth with severe hemophilia who obtain care annual within the United States HTC network are often insured and use preventive home treatments.
  • Hispanic males are more likely to develop inhibitors than non-Hispanic males.
  • Patients exposed to treatments using human blood may be exposed to certain viruses.

For more information about CDC’s work to improve the health of people with bleeding disorders, visit our page on Community Counts.