Johns Hopkins All Children's Hospital


Prospective Multicenter Evaluation of the Duration of Therapy for Thrombosis in Children

About this Study

The routine length of blood thinner treatment for most children with blood clots is 3 months. However, this routine is not backed by scientific evidence. Because blood thinners have a risk for causing bleeding, many physicians prescribe a shorter length (for example, 6 weeks) in children who they believe have a low risk for new blot clots to develop after this time, but this is not considered "standard". Blood thinner treatment less than 3 months should best be done as part of a careful scientific study (clinical trial). The Kids-DOTT trial will determine whether 6 weeks of blood thinner treatment is just as good as 3 months in such children.

This study also plans to learn more about the use of the blood thinner, dalteparin, in children. Dalteparin will be compared to other standard blood thinners used in children with blood clots.

Up to 750 children from over two dozen medical centers will participate.

Study Assessments

Study participation is expected to last for 2 years. Many of the assessments in this study will be completed as part of the standard of care visits. Other assessments will be completed for research only. The study team will let the participant know when an assessment is for research only.

  • Review of scans of the blood clot performed at diagnosis and at approximately 6 weeks after diagnosis
  • Randomization (like a flip of a coin) to either 6 weeks or 3 months duration of blood thinner treatment
  • Blood sample collection for research at 6 weeks and 3 months post-diagnosis
  • Brief follow-up phone calls at 2, 4 and 5 months following diagnosis
  • In-person follow-up at 6 weeks, and 3, 6, 12, and 24 months, after diagnosis.
  • Treatment diary to track when doses of the participants blood clot medication are missed
  • Tracking of medical events that happen to the participant

Study Participation Requirements

  • Recently diagnosed, for the first time, with an acute venous thrombosis (blood clot in your vein)
  • Age less than 21 years old at time of diagnosis of blood clot
  • Planned (or already on) treatment for the acute blood clot
  • No history of cancer
  • No prior history of treated blood clots
  • There are other requirements to participate. Please talk to the local coordinator and study doctor for more information.

Clinical Trials Q&A

  • What are clinical trials?
    A clinical trial is a research study in human volunteers to answer specific health questions. Carefully conducted clinical trials are the safest and fastest way to find treatments that work in people, and new ways to improve health.
  • Where can people find out about clinical trials?
    People can find information about clinical trials being conducted now by searching is an online database, managed by the National Library of Medicine. It provides information about both federally and privately supported clinical research in human volunteers. Find this study: Enter "Kids-DOTT" into the search box.
  • Are clinical trials safe?
    The Food and Drug Administration, Department of Health and Human Services,and children's hospital/university Institutional Review Boards work to protect participants in clinical trials and to ensure that children and their parents have reliable information as they decide whether to join a clinical trial. The federal government has regulations and guidelines for clinical research to protect participants from unreasonable risks.

    Although efforts are made to control the risks to clinical trial participants, some risks may be unavoidable because of the uncertainty inherent in medical research studies involving new medical treatments.

Q & A source:

Contact Information

Principal Investigator: Neil Goldenberg, M.D., Ph.D.
Phone: 727-767-6886
ACH IRB#: 12-0495

PTS Assessment training video

Launch Video (Password Required)

Kids-DOTT Investigator virtual meeting

Launch Video (Password Required)