Compression Hosiery to Avoid Post-Thrombotic Syndrome

  • days left to enroll
  • participants needed
  • sponsor
    Imperial College London
Updated on 16 September 2021
deep vein thrombosis
blood clot
deep venous thrombosis of lower extremity


Patients with a deep vein thrombosis (DVT) may develop long-term symptoms, e.g. lifelong leg pain, skin changes and occasionally ulceration, known as post-thrombotic syndrome (PTS). This affects about half of people with a history of DVT.

This randomised study aims to show whether the regular use of a compression stocking after DVT in the leg, prevents long-term pain, swelling and ulceration. Currently small trials show varied results and a large trial is required to answer the question.


Every year 1 in 1000 persons in the United Kingdom are diagnosed with a blood clot in the leg veins (deep vein thrombosis). In just under half of those with deep vein thrombosis, leg pain, swelling and skin breakdown (ulcers) can occur, a lifelong condition called post-thrombotic syndrome. This impacts upon a person's ability to work, their confidence and independence. In most patients there is no effective treatment and they lose income from unemployment. Ulcers, if they occur, require bandaging that needs to be changed twice weekly.

Treatment guidelines for deep vein thrombosis do not currently include the use of a compression stockings. They can sometimes be difficult to put on for those who cannot bend down, the stockings can slip or roll down, or become uncomfortable in hot weather. Stockings cost the National Health Service (NHS) approximately 50 every 6 months. The evidence for stockings comes from two early trials comparing patients wearing a stocking to those who did not.

There was a large benefit in both these trials for wearing a stocking, with no major side effects. In 2014, a Canadian group published a trial comparing wearing a compression stocking to wearing a non-compressive stocking. The rates of post-thrombotic syndrome were identical. The Canadian trial also suggested that only half of patients actually wear stockings, one reason the trial may have shown no difference. The Canadian trial suggested that stockings did not prevent future thrombosis or help leg pain. Whilst United Kingdom National Institute for Health and Care Excellence (NICE) recommendations are to avoid stockings after deep vein thrombosis, European recommendations are to still wear them. The contradictory results of these three trials have led us to design the CHAPS trial.

The aim of CHAPS is to confirm whether there is a real benefit of wearing stockings in addition to the standard treatment for deep vein thrombosis, which is blood thinning medication.

Adults with a first deep vein thrombosis can join the trial. They will be randomly allocated to receive either blood thinning medication, or blood thinning medication and an additional compression stocking. This is a tight, custom fitted stocking that they will be asked to wear whilst they are awake as much as possible for between 6-30 months. Patients will be aware of which group they are in, but will be asked not to wear the stocking when they come for their assessment. This keeps the researchers impartial.

Condition deep venous thrombosis of lower extremity, post thrombotic syndrome, Thrombosis, Venous Thrombosis, Deep Vein Thrombosis Leg, Deep Vein Thrombosis, Blood Clots, Venous stasis, deep venous thrombosis
Treatment Graduated compression stocking
Clinical Study IdentifierNCT04103112
SponsorImperial College London
Last Modified on16 September 2021


Yes No Not Sure

Inclusion Criteria

Symptomatic presentation of first deep vein thrombosis, <2 weeks from diagnosis
Imaging confirmed, lower limb deep vein thrombosis (popliteal, femoral, iliac or combination)
Ability to give informed consent
Age 18 or over

Exclusion Criteria

Life expectancy < 2 years
Contraindication to wearing graduated compression stockings
Previously intolerant of or already wearing graduated compression stockings for more than 1 month
Ankle brachial pressure index (ABPI) <0.8 or pedal pulses absent
Bilateral deep vein thrombosis
Previous chronic venous insufficiency (patients with existing chronic skin changes or ulceration, defined as C4,5,6 by Clinical Etiological Anatomical Pathophysiological (CEAP) classification)
Pre-existing post thrombotic syndrome, significant leg pain (e.g. knee arthritis, spinal claudication) or oedema (e.g. lymphoedema)
Newly diagnosed cancer, metastatic cancer, or cancer undergoing active treatment or palliation
Contraindication to anticoagulation
Known allergy to fabric in compression stockings
Clear my responses

How to participate?

Step 1 Connect with a study center
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer  to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact


Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider


Browse trials for

Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note