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Completed

NCT Number: NCT00143598

The SOX Trial: Compression Stockings to Prevent the Post-Thrombotic Syndrome

The purpose of this study is to determine whether elastic compression stockings used for 2 years are effective in preventing the post-thrombotic syndrome in patients with symptomatic proximal deep venous thrombosis.

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Key information

Conditions

Deep Venous Thrombosis Cardiovascular Diseases Embolism and Thrombosis Peripheral Vascular Diseases Phlebitis Postphlebitic Syndrome Postthrombotic Syndrome Thrombosis Vascular Diseases Venous Insufficiency Venous Thrombosis

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

Victoria Heart Institute Foundation, Victoria, British Columbia, Canada

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About this study

The post-thrombotic syndrome (PTS) is a frequent, burdensome and costly condition that occurs in about one third of patients after an episode of deep vein thrombosis (DVT). Affected patients have chronic leg pain and swelling, and sometimes develop skin ulcers. At present, there is little to offer for the treatment of this condition. Prevention of PTS is the key to reducing its burden on patients and society. Elastic compression stockings (ECS) could be helpful in preventing PTS, however data on their effectiveness are scarce and conflicting.

Comparison(s): Knee-length, 30-40 mm Hg (Class II), graduated ECS worn on the DVT-affected leg daily for 2 years compared to knee-length, inactive (i.e. no compression) stocking, identical in appearance to active ECS, worn on the DVT-affected leg daily for 2 years.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Consecutive patients with a first, symptomatic, objectively confirmed proximal DVT diagnosed within the last 14 days (with or without concurrent distal DVT or pulmonary embolism)
  • Who have no contraindications to standard treatment with heparin and/or warfarin, and
  • Who provide informed consent to participate

Exclusion criteria

  • Contraindication to compression stockings
  • Limited lifespan (estimated < 6 months)
  • Geographic inaccessibility preventing return for follow-up visits
  • Inability to apply stockings daily and unavailability of a caregiver to apply stockings daily
  • Treatment of acute DVT with thrombolytic agents

Treatment and study plan

Knee-length, graduated elastic compression stocking

Device

Worn daily for 2 years, 30-40 mm Hg

Knee-length, placebo stocking

Device

Worn daily for two years

Primary outcomes

  1. Incidence of Post-thrombotic Syndrome (PTS)

    Time frame: During 2-year follow up

Secondary outcomes

  1. Severity of PTS, Including Incidence of Venous Ulcer

    Time frame: 6-24 months.

    Highest Villalta at or after 6 month visit

    The Villalta Scale for assessment of the post-thrombotic syndrome The Villalta scale has a range of 0-33. A Villalta scale score >4 indicates post-thrombotic syndrome (severity of post-thrombotic syndrome is categorized as 5-9 points, mild; 10-14 points, moderate; >14 points or presence of an ulcer, severe).

    Higher values signify worse outcome. Points on each item in the scale are simply summed to a total score.

  2. Incidence of Objectively Confirmed Recurrent Venous Thromboembolism (VTE), Death From VTE and Major Bleeding

    Time frame: During 2-year follow up

  3. Quality of Life

    Time frame: 24 months

    The SF-36 is a well-validated generic quality-of-life (QOL) instrument. It includes questions on both physical and mental health. Higher scores indicate a better QOL. The VEINES-QOL is a venous-disease specific QOL measure that consists of 25 items that quantify venous disease effect on QOL, and an embedded symptom sub-questionnaire (VEINES-Sym) with 10 items that measures venous symptoms. Higher scores are associated with better QOL.

    The VEINES-QOL/Sym and SF-36 use the standard method for scoring questionnaires with items with different response scales that is now routinely used. Raw scores are first transformed to z score equivalents (mean, 0; standard deviation, 1), which then are transformed to T scores (mean, 50; standard deviation, 10) to give an easily understood range of scores. A person-specific estimate is imputed for any missing item in cases where the patient answered at least 50% of the items in the scale.

Sponsors and collaborators

Lead sponsor

Sir Mortimer B. Davis - Jewish General Hospital

Other

Collaborators

  • Canadian Institutes of Health Research (CIHR)
  • Sigvaris Corporation

Registry information

Official study title

The SOX Trial: Compression Stockings to Prevent the Post-Thrombotic Syndrome After Symptomatic Proximal Deep Venous Thrombosis

Important dates

Study start
2004
Primary completion
2012
Study completion
2012
First posted
Sep 2, 2005
Registry last updated
Aug 18, 2014

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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