Clinical Trial: Risk of Intracranial Hemorrhage in Users of Oral Antithrombotic Drugs

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: Risk of Intracranial Hemorrhage in Users of Oral Antithrombotic Drugs: a Nationwide Study

Brief Summary:

The true incidence and risks of intracranial hemorrhage (ICH) in patients on various antithrombotic treatments remain unknown. Here a nationwide study is conducted to investigate the risk for and incidence rates of ICH in users and non-users of various oral antithrombotic drugs in Norway between 2008 through 2014.

Hopefully, this study will contribute to a more responsible prescription pattern of antithrombotic medications.


Detailed Summary:

The most serious adverse effect of antithrombotic therapy is bleeding. Combinations of antithrombotic agents are now frequently used (e.g. after use of drug eluting stents or after ischemic stroke), and this may lead to an increased frequency of significant bleeding complications. Among hemorrhagic complications of antithrombotic drugs, intracranial hemorrhage (ICH) may have particularly devastating consequences with high morbidity, disability and even mortality rates. Intracerebral hemorrhage (hemorrhagic stroke) is generally associated with a higher risk for death and incurs greater loss of health over a lifetime than ischemic stroke.

This makes antithrombotic therapy a double-edged sword. Although a certain risk for bleeding may be acceptable in the context of even greater protection against ischemic events, it is important to quantify the magnitude of bleeding risk. So far the efficacy and safety profile of antithrombotic agents are generally assessed in randomized controlled trials (RCT). However, extrapolating the results from randomized clinical trials to the general patient population in this context is challenging. Patients who participate in clinical trials are frequently highly selected and therefore somewhat unrepresentative. In addition, their numbers are limited and the treatment period is often much shorter than in routine management of a chronic disease or condition. Finally, patients in clinical trials are often monitored more closely than in routine practice.

The incidence of intracranial hemorrhage due to antithrombotic therapy could theoretically be monitored by post-marketing surveillance by including spontaneously reported events. Unfortunately, it seems this does not provide more reliable estimates. A recent study from Finland has shown that bleeding complications due to oral anticoagulation with War
Sponsor: St. Olavs Hospital

Current Primary Outcome: incidence rate of intracranial hemorrhage (ICH) requiring hospitalization [ Time Frame: 6 years ]

We will determine the incidence rates of ICH in users and non-users of oral antithrombotic treatment by linking data from Norwegian Patient Register (NPR) and the Norwegian prescription database.


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • overall survival following ICH [ Time Frame: 6 years ]
    comparison of users and non-users of oral antithrombotic drugs
  • proportion of ICH patients undergoing neurosurgical procedures [ Time Frame: 6 years ]
    comparison of users and non-users of oral antithrombotic drugs


Original Secondary Outcome: Same as current

Information By: St. Olavs Hospital

Dates:
Date Received: June 22, 2015
Date Started: May 2015
Date Completion:
Last Updated: April 27, 2017
Last Verified: April 2017