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Completed Not applicable Interventional Results available

Study to Develop a Reliable Nomogram That Incorporates Clinical and Genetic Information

ClinicalTrials.gov ID: NCT00401414

Public ClinicalTrials.gov record NCT00401414. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 11, 2026, 2:30 PM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Official title

CReating an Optimal Warfarin Nomogram (CROWN) Trial

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

In this research study, the investigators are trying to find a better way to set the dose of a common blood-thinning medication. Patients with blood clots or a risk of blood clots (or stroke) sometimes have to take an approved medication called warfarin. Warfarin is a commonly prescribed, approved blood thinning medicine taken by mouth. There is a certain level of warfarin that is best for each patient at a particular time. It is hard for a doctor to choose and maintain the right dose of warfarin for each patient. Too much or too little warfarin in the blood can cause serious health problems. A "nomogram" is a tool that helps doctors decide on the right dose of warfarin. The usual way for finding the right dose of warfarin is for doctors to take an educated guess and use a "trial and error" approach. Patients have frequent blood tests to help doctors keep track of how well the dose level is working. Up until now, if a patient had good blood test results over half of the time, that was as well as doctors could do. The purpose of this study is to see whether the investigators can create a reliable new warfarin nomogram that will allow them to dose a patient correctly more often, perhaps about 3 times out of 4. The nomogram the investigators are studying uses information about a patient's health and genes to decide on the best dose of warfarin. The investigators don't yet have a reliable, safe way to choose the correct dose. In this study, the investigators will use a genetic blood test to try to find a better way. Genes are the parts of each living cell that allow characteristics to be passed on from parents to children. The investigators know that people with certain genes seem to respond to warfarin in a certain way. From a blood sample, the investigators can look at patients' genes and try to predict the response to the blood-thinning medication. There will be about 500 subjects taking part in this study. They will come from participating Partners' Hospitals, including Brigham and Women's Hospital, Massachusetts General Hospital, Faulkner Hospital, Newton-Wellesley Hospital, Spaulding Rehabilitation Hospital, and North Shore Medical Center. The U.S. Food and Drug Administration (FDA) has approved warfarin for use as a blood thinner.

Study identification

NCT ID
NCT00401414
Recruitment status
Completed
Study type
Interventional
Phase
Not applicable
Enrollment
344 participants

Conditions and interventions

Eligibility (public fields only)

Age range
18 Years and older
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Dec 31, 2006
Primary completion
May 31, 2011
Completion
May 31, 2011
Last update posted
Aug 29, 2013

2007 – 2011

United States locations

U.S. sites
2
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
Massachusetts General Hospital Boston Massachusetts 02114
Brigham and Women's Hospital Boston Massachusetts 02115

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

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About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT00401414, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Aug 29, 2013 · Synced Sep 11, 2026

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