0
We're unable to sign you in at this time. Please try again in a few minutes.
Retry
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
Retry
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Other Articles |

Levels of Equivalence for Various Measurements of Coumarin Activity

R. J. Tat, M.D.; A. E. Lewis, M.D.
JAMA. 1962;180(9):744-746. doi:10.1001/jama.1962.03050220036007c.
Text Size: A A A
Published online

THE PURPOSE of the studies reported here is to determine the statistical relationship between the measurements of anticoagulation by the one-stage method of Quick, Owren's thrombotest, and the prothrombin-proconvertin method (hereinafter referred to as P and P). Included is an evaluation of the Lee-White clotting time as an over-all test of the clotting mechanisms.

The adequacy of prothrombin measurements for the regulation of the dose of coumarin has been questioned. It has been pointed out that coumarin derivatives depress several clotting factors. Presumably, each factor involved is depressed proportionately in most cases. However, in occasional instances a disproportionate depression of one or more factors may occur. The nature of the assay methods for prothrombin precludes the recognition of this possibility until hemorrhage has occurred.

Owren, in an attempt to solve this problem, has presented a reagent, thrombotest, in which, he claims, the relative concentrations of clotting factors are balanced at

Topics

Sign in

Create a free personal account to sign up for alerts, share articles, and more.

Purchase Options

• Buy this article
• Subscribe to the journal

First Page Preview

View Large
First page PDF preview

Figures

Tables

References

Letters

CME
Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.

Multimedia

Some tools below are only available to our subscribers or users with an online account.

Sign in

Create a free personal account to sign up for alerts, share articles, and more.

Purchase Options

• Buy this article
• Subscribe to the journal

Related Content

Customize your page view by dragging & repositioning the boxes below.

Jobs
brightcove.createExperiences();