Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to site content Skip directly to page options
CDC Home

Universal Data Collection (UDC) System

mother and child with doctorOne of the major challenges facing scientists who work on rare disorders, such as hemophilia, is lack of uniform health data. To address this issue and to advance health research, CDC created a national public health surveillance project called the Universal Data Collection (UDC) system.  UDC is carried out with the help of federally funded hemophilia treatment centers (HTCs) in the United States and its territories.

Since the system began in 1998, about 24,000 people with bleeding disorders have contributed their health data by participating in the UDC program. More than 80% of all people with hemophilia who receive care at HTCs participate.


UDC Data Reports

UDC data and reports are available to HTC staff. Staff at each HTC can download electronic files containing UDC data collected from participants at their HTC. In addition, continuously updated national and regional reports are available to the public on CDC’s website. 

UDC Data Reports »


Important Findings

Several articles about studies that used UDC data have been published. A few of the findings so far are:

  • Youth with hemophilia are just as likely as youth among the general population to be overweight.1
  • Youth with hemophilia who are overweight are more likely to have decreased joint mobility than those who are not overweight.1
  • 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.2
  • No new infections of hepatitis A, hepatitis B, hepatitis C, or HIV have been linked to blood products used to treat bleeding disorders.3
  • 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 clotting factor  products before 1986. Hemophilia-related (bleeding) causes of death were less common (12%).4
  • 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.5
  • The rate of new inhibitors (antibodies to clotting factor 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.6

Learn more about the UDC system



  1. Soucie JM, Cianfrini C, Janco RL, et al.  Joint range of motion limitations among young males with hemophilia:  Prevalence and risk factors.  Blood 2004; 103:2467-73.

  2. Ashrani AA, Key NS, Soucie JM,Duffy N, Forsyth A, Geraghty S and the Universal Data Collection Project Investigators.  Septic arthritis in males with haemophilia.  Haemophilia 2008; 14:494-503.

  3. CDC.  Blood Safety Monitoring Among Persons with Bleeding Disorders.  MMWR January 3,2003;51(51-52);1152-54.

  4. Poster Presentation. Larsen NM et al:  Mortality Among Patients Treated at Federally Funded Hemophilia Treatment Centers (HTCs). National Hemophilia Foundation Annual Meeting October 2007.

  5. Kulkarni R, Soucie JM, Lusher J, et al.  Sites of initial bleeding episodes, mode of delivery and age of diagnosis in babies with haemophilia diagnosed before the age of 2 years:  a report from the Centers for Disease Control and Prevention’s (CDC) Universal Data Collection (UDC) project.  Haemophilia e-pub July 22, 2009. 

  6. Kempton CL, Soucie JM, Abshire TC.  Incidence of inhibitors in a cohort of 838 males with hemophilia A previously treated with factor VIII concentrates.  J Thromb Haemostasis 2006; 4:2576-2581.




CDC 24/7 – Saving Lives. Protecting People. Saving Money Through Prevention. Learn More About How CDC Works For You…


Contact Us:
  • Centers for Disease Control and Prevention

    National Center on Birth Defects and Developmental Disabilities

    Division of Blood Disorders

    1600 Clifton Road
    MS E-87
    Atlanta, GA 30333
  • 800-CDC-INFO
    TTY: (888) 232-6348
    New Hours of Operation
    8am-8pm ET/Monday-Friday
    Closed Holidays
  • The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Rd. Atlanta, GA 30333, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 -
A-Z Index
  1. A
  2. B
  3. C
  4. D
  5. E
  6. F
  7. G
  8. H
  9. I
  10. J
  11. K
  12. L
  13. M
  14. N
  15. O
  16. P
  17. Q
  18. R
  19. S
  20. T
  21. U
  22. V
  23. W
  24. X
  25. Y
  26. Z
  27. #