Prolongation of the Interval Between Prothrombin Time Tests in Stable Patients II (PRINT-II)
2014年3月18日 更新者：Sam Schulman、McMaster University
Prolongation of the Interval Between Prothrombin Time Tests in Stable Patients II (the PRINT II Study): a Randomized Controlled, Non-inferiority Trial Comparing 4-weekly With 12-weekly Testing and Dose-assessment
More than 2 million patients in North America are treated with warfarin - a "blood thinner" - to prevent blood clots in arteries or veins.
The treatment has to be monitored with a blood test and the dose changed accordingly every 1-4 weeks.
One third of the patients have very stable results and hardly ever have to change the dose.
The investigators wish to show that the level of control of the treatment with warfarin in these very stable patients is not worse with 12-weekly testing.
A pilot study the investigators performed indicated that 12-weekly testing would be safe but this has to be confirmed in a large study.
One third of patients taking warfarin have not had any changes in the dose for the past 6 months or longer.
These patients will be asked about participation in the study.
They will be randomized to testing and dosing every 4 or 12 weeks.
Each patient is in the study until it ends, which will be minimum 1 year and can be up to about 4 years.
The study is designed to show that 12-weekly testing does not significantly increase the risk for major bleeding or blood clots.
The results would be important for a large number of patients.
An increase of the interval between blood tests from 4 to 12 weeks would reduce the burden for these patients on life-long treatment considerably.
研究概览
详细说明
The study is a randomized, controlled, open-label, multi-center non-inferiority trial to demonstrate that the interval between internation normalized ration (INR) tests can be extended from the recommended 4 weeks to 12 weeks for patients with stable INRs.
PROBE design.
Patients receiving warfarin therapy that have exhibited INR stability, defined as no change in maintenance dose for at least 6 months, are potentially eligible for enrolment in the study.
The primary outcome is a composite of major bleeding (ISTH criteria) plus objectively verified arterial or venous thromboembolism (excluding superficial thrombophlebitis) plus death related to thromboembolism.
Justification: the study is not reflecting a "trade-off" scenario where one regimen is expected to be more effective at the cost of increased harm compared to the other regimen.
Conversely, the potential disadvantage of the experimental regimen in this trial is increased variability in INR, which may result in an increased rate of low as well as high INRs and therefore potentially an increase of both types of clinical events.
研究类型
介入性
阶段
- 第三阶段
联系人和位置
本节提供了进行研究的人员的详细联系信息，以及有关进行该研究的地点的信息。
学习地点
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Ontario
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Hamilton、Ontario、加拿大、L8L 2X2
- Hamilton Health Sciences - General Hospital
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参与标准
研究人员寻找符合特定描述的人，称为资格标准。这些标准的一些例子是一个人的一般健康状况或先前的治疗。
资格标准
适合学习的年龄
18年 及以上 (成人、年长者)
接受健康志愿者
不
有资格学习的性别
全部
描述
Inclusion Criteria:
- long-term warfarin for prophylaxis of arterial embolism due to atrial fibrillation or mechanical heart valve replacement OR secondary prophylaxis after VTE
- therapeutic INR range of 2.0-3.0 or 2.5-3.5
- anticoagulation therapy has been managed by the study site for at least 6 months prior to enrollment
- warfarin maintenance dose has remained unchanged for the previous 6 months or longer
Exclusion Criteria:
- Age < 18 years
- Life expectancy of less than 1 year
- Congestive heart failure or other diagnosis where the condition or its treatment is expected to affect the stability of INR (e.g. cancer requiring chemotherapy)
- Attending physician believes that patient is not suitable for the study (for instance, psychiatric disorder; history of non-compliance; newly diagnosed disease which by itself, via the treatment required or the effects thereof may cause instability of INRs)
- Patients who perform self-testing
- Geographic inaccessibility
- Failure to obtain written consent
学习计划
本节提供研究计划的详细信息，包括研究的设计方式和研究的衡量标准。
研究是如何设计的？
设计细节
- 主要用途：治疗
- 分配：随机化
- 介入模型：并行分配
- 屏蔽：无（打开标签）
武器和干预
参与者组/臂 |
干预/治疗 |
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无干预：Standard interval between PT testing
Prothrombin time (PT) is tested every 4 weeks, according to American College of Chest Physicians (ACCP) Guidelines up to 2008 for stable patients on warfarin.
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实验性的：Prolonged interval between PT testing
Prothrombin time (PT) is tested every 12 weeks, according to suggestion in American College of Chest Physicians (ACCP) Guidelines of 2012 for stable patients on warfarin.
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Patients in the intervention group will be scheduled for prothrombin time testing and dosing of warfarin every 12 weeks instead of every 4 weeks.
This has been suggested in the latest edition of the ACCP guidelines as a possibility for very stable patients.
In order to change this from a suggestion to a formal recommendation a study powered for clinically important outcomes is needed.
其他名称：
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研究衡量的是什么？
主要结果指标
结果测量 |
措施说明 |
大体时间 |
|---|---|---|
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Composite of major bleeding and objectively verified arterial or venous thromboembolism
大体时间：Average 3 years
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The justification for a composite outcome including both bleeding and thromboembolism is that the study is not reflecting a "trade-off" scenario where one regimen is expected to be more effective at the cost of increased harm compared to the other regimen.
Conversely, the potential disadvantage of the experimental regimen in this trial is increased variability in prothrombin time, which may result in an increased rate of short as well as long prothrombin times and therefore potentially an increase of both types of clinical events.
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Average 3 years
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次要结果测量
结果测量 |
措施说明 |
大体时间 |
|---|---|---|
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All-cause mortality
大体时间：Average 3 years
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Average 3 years
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Any bleeding
大体时间：Average 3 years
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This is the composite of major and minor bleeding
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Average 3 years
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合作者和调查者
在这里您可以找到参与这项研究的人员和组织。
出版物和有用的链接
负责输入研究信息的人员自愿提供这些出版物。这些可能与研究有关。
一般刊物
- Schulman S, Parpia S, Stewart C, Rudd-Scott L, Julian JA, Levine M. Warfarin dose assessment every 4 weeks versus every 12 weeks in patients with stable international normalized ratios: a randomized trial. Ann Intern Med. 2011 Nov 15;155(10):653-9, W201-3. doi: 10.7326/0003-4819-155-10-201111150-00003.
- Pengo V, Barbero F, Biasiolo A, Pegoraro C, Cucchini U, Iliceto S. A comparison between six- and four-week intervals in surveillance of oral anticoagulant treatment. Am J Clin Pathol. 2003 Dec;120(6):944-7. doi: 10.1309/U716-4E0X-H5UE-RKRV.
研究记录日期
这些日期跟踪向 ClinicalTrials.gov 提交研究记录和摘要结果的进度。研究记录和报告的结果由国家医学图书馆 (NLM) 审查，以确保它们在发布到公共网站之前符合特定的质量控制标准。
研究主要日期
学习开始
2014年4月1日
初级完成 (预期的)
2018年4月1日
研究完成 (预期的)
2018年10月1日
研究注册日期
首次提交
2012年7月21日
首先提交符合 QC 标准的
2012年7月26日
首次发布 (估计)
2012年7月31日
研究记录更新
最后更新发布 (估计)
2014年3月20日
上次提交的符合 QC 标准的更新
2014年3月18日
最后验证
2014年3月1日
更多信息
此信息直接从 clinicaltrials.gov 网站检索，没有任何更改。如果您有任何更改、删除或更新研究详细信息的请求，请联系 register@clinicaltrials.gov. clinicaltrials.gov 上实施更改，我们的网站上也会自动更新.