Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


New DVT guidelines: No evidence to support 'economy class syndrome'

Oral contraceptives, sitting in a window seat, advanced age, and pregnancy increase DVT risk in long-distance travelers

New evidence-based guidelines from the American College of Chest Physicians (ACCP) address the many risk factors for developing a deep vein thrombosis (DVT), or blood clot, as the result of long-distance travel.

These risk factors include the use of oral contraceptives, sitting in a window seat, advanced age, and pregnancy. The Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines, published in the February issue of the journal CHEST, also suggest there is no definitive evidence to support that traveling in economy class can lead to the development of a DVT, therefore, dispelling the myth of the so-called "economy class syndrome."

"Traveling in economy class does not increase your risk for developing a blood clot, even during long-distance travel; however, remaining immobile for long periods of time will," said guideline co-author Mark Crowther, MD, Department of Medicine, McMaster University, Hamilton, Ontario, Canada. "Long-distance travelers sitting in a window seat tend to have limited mobility, which increases their risk for DVT. This risk increases as other factors are present." DVT is a serious condition that can lead to a potentially fatal blockage in the lung known as a pulmonary embolism (PE).


Although developing a DVT/PE as the result of long-distance travel is unlikely in most cases, the guidelines note that for long-distance flights, the following factors may increase your risk of developing a DVT/PE and related complications:

Previous DVT/PE or known thrombophilic disorder
Recent surgery or trauma
Advanced age
Estrogen use, including oral contraceptives
Sitting in a window seat
Conversely, the guidelines suggest there is no definitive evidence to support that dehydration, alcohol intake, or sitting in economy class (compared with sitting in business class) increases your risk for developing a DVT/PE resulting from long-distance flights.


For travelers on flights of 6 hours or more who have an increased risk for DVT/PE, the ACCP recommends frequent ambulation, calf muscle stretching, sitting in an aisle seat if possible, or the use of below-knee graduated compression stockings (GCS). For long-distance travelers who are not at increased risk for DVT/PE, the guidelines suggest against the use of GCS. In addition, the guidelines suggest against the use of aspirin or anticoagulant therapy to prevent DVT/PE in long-distance travelers. For travelers who are considered to be at particularly high risk for DVT/PE, the use of antithrombotic agents should be considered on an individual basis because the adverse effects may outweigh the benefits.

"Symptomatic DVT/PE is rare in passengers who have returned from long flights; however the association between air travel and DVT/PE is strongest for flights longer than 8 to 10 hours," said Dr. Crowther. "Most passengers who do develop a DVT/PE after long-distance travel have one or more risk factors."


In addition to long-distance travel, the ACCP guidelines include more than 600 recommendations for the prevention, diagnosis, and treatment of thrombosis, addressing a comprehensive list of clinical conditions. These clinical conditions include medical, surgery, orthopedic surgery, atrial fibrillation, stroke, cardiovascular disease, pregnancy, and neonates and children, among others. Key advances in this edition of the guidelines include a stronger focus on risk stratification of patients, which suggests clinicians should consider a patient's risk for DVT/PE before administering or prescribing a prevention therapy.

"There has been a significant push in health care to administer DVT prevention for every patient, regardless of risk. As a result, many patients are receiving unnecessary therapies that provide little benefit and could have adverse effects," said Guidelines Panel Chair Gordon Guyatt, MD, FCCP. "The decision to administer DVT prevention therapy should be based on the patients' risk and the benefits of prevention or treatment." The new guidelines also take a more patient-focused approach by considering patient values and preferences regarding antithrombotic therapy and prevention.

The guidelines are endorsed by the following medical associations: the American Association for Clinical Chemistry, American College of Clinical Pharmacy, American Society of Health-System Pharmacists, American Society of Hematology, International Society of Thrombosis and Hemostasis, and the American College of Obstetrics and Gynecology (pregnancy article only).

For more information about the guidelines and accompanying clinician resources, visit and follow #AT9 on Twitter. Patient resources related to the guidelines are available through OneBreath, an initiative of The CHEST Foundation, the philanthropic arm of the ACCP.


The ACCP represents 18,400 members who provide patient care in the areas of pulmonary, critical care, and sleep medicine in the United States and more than 100 countries throughout the world. The mission of the ACCP is to promote the prevention, diagnosis, and treatment of chest diseases through education, communication, and research. CHEST is the official peer-reviewed publication of the ACCP. More than 30,000 readers worldwide turn to CHEST in print and 400,000 people view CHEST online each month for the latest in chest-related medicine. For more information about the ACCP, visit or follow the ACCP via social media at and @accpchest.

Jennifer Stawarz | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht NIH scientists describe potential antibody treatment for multidrug-resistant K. pneumoniae
14.03.2018 | NIH/National Institute of Allergy and Infectious Diseases

nachricht Researchers identify key step in viral replication
13.03.2018 | University of Pittsburgh Schools of the Health Sciences

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Physicists made crystal lattice from polaritons

20.03.2018 | Physics and Astronomy

Mars' oceans formed early, possibly aided by massive volcanic eruptions

20.03.2018 | Physics and Astronomy

Thawing permafrost produces more methane than expected

20.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>