Preventing Hospital-Associated Venous Thromboembolism


Hospital-Associated Venous Thromboembolism as a Public Health Problem

Pulmonary embolism (PE) and deep vein thrombosis (DVT), collectively known as venous thromboembolism (VTE), represent a major public health problem that affects 350,000 to 600,000 Americans annually.1 Estimates vary widely, but the overall annual prevalence may be increasing.2 VTE is primarily a problem of sick or injured patients who are hospitalized or were recently hospitalized,3,4 and it is frequently estimated to be among the most common preventable causes of hospital death.5-7

Symptomatic DVT and PE are associated with extended duration of inpatient stays and high (10-15 percent) fatality rates. VTE generally requires therapeutic anticoagulation for a minimum of 3 months.8,9 This therapeutic anticoagulation is associated with 1 to 2 percent major bleeding per patient year, resulting in fatal bleeding at least 0.1 to 0.3 percent per patient year in clinical trials. In real-world practices, the rates are much higher.10-12

When patients survive the VTE event and acute course of anticoagulant therapy—and all the inconvenience, anxiety, and cost that represents—they are still at risk for other complications. More than 20 percent of patients with proximal DVT/PE will suffer a recurrent event once anticoagulation has been discontinued, along with all the readmissions, mortality, and morbidity risk that entails.13 Furthermore, 30 to 50 percent of DVT patients will develop postthrombotic syndrome,14 and an estimated 4 percent of PE patients will develop chronic thromboembolic pulmonary hypertension.15 Patients and their families relay powerful personal stories related to loss of function, difficulty with anticoagulant therapy, fiscal burden, and fear of recurrence.

Thromboprophylaxis for at-risk inpatients can reduce VTE by 30 to 65 percent, has a low incidence of major bleeding complications, and has well-documented cost-effectiveness.16,17 Numerous guidelines from authoritative bodies outlining appropriate use of thromboprophylaxis are available,16,18-24 yet study after study reflects unacceptably low rates of thromboprophylaxis in patients at risk.25-30 For example, a recent cross-sectional international study of almost 70,000 patients in 358 hospitals found that appropriate prophylaxis was administered in only 58.5 percent of surgical and 39.5 percent of medical inpatients at risk for VTE27; another U.S. registry found only 42 percent of patients with hospital-associated DVT received prophylaxis within 30 days prior to diagnosis.30 This constellation of facts presents a powerful imperative for improvement.

This "implementation gap" in VTE prophylaxis between evidence-based best practice and actual practice in the real world has not gone unnoticed as a major opportunity for improvement. In 2008, the U.S. Surgeon General produced a call-to-action document for VTE prevention.1 In addition, key goals for VTE prevention are in place from the National Quality Forum and the Joint Commission,31,32 mirrored by criteria for meaningful use criteria for electronic health records. The Surgical Care Improvement Project has widely used measures for VTE prevention,33 and VTE Prevention is one of the focus areas of the Partnership for Patients, a major effort from the Centers for Medicare & Medicaid Services (CMS) to foster accelerated improvement.34

Reports commissioned by the Agency for Healthcare Research and Quality (AHRQ) called thromboprophylaxis the "number one" patient safety practice,17 and a 2013 update continues to list improved prophylaxis for VTE as a top 10 patient safety strategy to act on now.35 The American Public Health Association has stated that the "disconnect between evidence and execution as it relates to DVT prevention amounts to a public health crisis."36

Purpose of This Guide

In 2008, AHRQ published Preventing Hospital-Acquired Venous Thromboembolism: A Guide for Effective Quality Improvement.37 That guide was based on success in VTE prevention38-41 and quality improvement principles at the University of California, San Diego. The purpose of that publication and this update is to assist hospital improvement teams to close the implementation gap as effectively and efficiently as possible.

While guidelines often focus on defining best practice, this work focuses on the specifics of how to ensure those best practices are reliably delivered in your local inpatient environment. Multiple barriers and "failure modes" must be overcome to reliably provide prophylaxis to those at risk while avoiding over-prophylaxis of those who are not.

It turns out that VTE prophylaxis is a somewhat complex process in the very complex hospital environment. As systems, hospitals are perfectly designed to achieve the results they attain; improving care generally involves changing the basic design of elements of that system and carefully monitoring to adjust the interventions and ensure that the change leads to the desired improvement. The basic principles and essential elements to reach breakthrough levels of improvement in care have not changed since they were listed in the first edition:

  • Institutional support and prioritization for the initiative, expressed in terms of a meaningful investment in time, equipment, personnel, and informatics, and a sharing of institutional improvement experience and resources to support any project needs.
  • A multidisciplinary team or steering committee focused on reaching VTE prophylaxis targets and reporting to key medical staff committees.
  • Reliable data collection and performance tracking.
  • Specific goals or aims that are ambitious, time defined, and measurable.
  • A proven quality improvement (QI) framework to coordinate steps toward breakthrough improvement.
  • Evidence-based protocols that standardize VTE risk assessment and prophylaxis.
  • Institutional infrastructure, policies, practices, and educational programs that promote use of the protocol.

The protocol that standardizes VTE risk assessment is so fundamental that it should not merely exist but also be embedded in patient care. High-reliability design may then be used to enhance effective implementation.

What's New in This Guide

This revision reflects important changes in the environment, new guidelines, and lessons learned. More specifically, this version presents:

  1. Lessons from collaboratives and success stories: The first edition of this guide was used as the centerpiece of a number of multisite collaborative improvement efforts funded by AHRQ. This experience in a wide variety of hospitals has provided insight into what works and, perhaps just as important, what does not work in real-world settings.42,43 Many others have also published or shared outlines of what works and what did not work in their settings, and this guide has attempted to collate some of the strategies that may have portability across a variety of settings.44-64
  2. Context of new evidence and new guidelines from the American College of Physicians, the 9th edition of the American College of Chest Physicians on Antithrombotic Therapy and Prevention of Thrombosis (AT9), and the American Academy of Orthopedic Surgeons (AAOS): The ACP Guideline (ACP1)18 and supporting review65 address VTE prophylaxis in nonsurgical patients, while the AT9 guidelines8 also cover a wide variety of patient populations in separate guidelines for medical inpatients,19 orthopedic patients,21 and nonorthopedic surgical patients.20 The complexity of the new guidelines, lack of consensus about VTE risk assessment, varied estimates of risk and benefit, and significant changes from AT8 have contributed to uncertainty about best practices in VTE prevention and design for VTE prevention protocols.
  3. Increased use of electronic health records (EHRs), computerized physician order entry (CPOE), and advanced information technology: This revision features more examples of tools in this new environment and explores the "good, the bad, and the ugly" aspects of implementing protocols in the emerging computerized medical environment. We present tools to illustrate clinical decision support in CPOE and EHR formats, which go above and beyond the Department of Health and Human Services' meaningful use criteria for VTE prophylaxis.
  4. New measures: New and improved metrics for tracking the adequacy of VTE prophylaxis, including information on using measurement with concurrent intervention (aka measure-vention) are reviewed. Similar strategies to improve ambulation and address over-prophylaxis have been incorporated, as has a discussion of new ICD-9a codes for hospital-associated VTE (HA-VTE) that have been released since the last version of this guide was published. Guidance that outlines optimal use of administrative data to track HA-VTE is also updated to include the present on admission indicator and to capture patients readmitted with new VTE within 30 days of a prior hospital stay.
  5. New methods to improve on reliable delivery and enhanced adherence to VTE prophylaxis orders (as opposed to focusing solely on getting the order correct): This is important in view of commonly reported deficiencies in adhering to mechanical VTE prophylaxis (50-60 percent) and pharmacologic prophylaxis (10-20 percent of doses commonly not delivered).
  6. New information focusing on the importance of patient engagement and education: This includes transitions of care, indications for extended-duration prophylaxis, and prophylaxis in special populations (e.g., obese patients, patients with renal failure, and patients going to skilled nursing or rehab facilities).
  7. Frequently asked questions for VTE prevention and a concise executive summary.

How To Use the Guide and Related Tools and Resources

QI projects can help health care facilities close the gap between optimal care and the care that is actually delivered. The chapters in this guide follow the logical steps of a QI project. QI, however, often unfolds along several parallel fronts. Many steps in an initiative occur simultaneously and are often interdependent, so readers should feel comfortable skipping to the chapters that are most pertinent to them while keeping the larger framework in mind.

a ICD-9 is the International Classification of Diseases, 9th Edition.

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Page last reviewed March 2016
Page originally created February 2016
Internet Citation: Preface. Content last reviewed March 2016. Agency for Healthcare Research and Quality, Rockville, MD.
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