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

Deep Venous Thrombosis Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00143598
• Other study ID #: MCT-63142
• Secondary ID: ISRCTN71334751
• Status: Completed
• Phase: Phase 3
• First received: September 1, 2005
• Last updated: August 15, 2014
• Start date: June 2004
• Est. completion date: February 2012

Study information

• Verified date: August 2014
• Source: Sir Mortimer B. Davis - Jewish General Hospital
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Health Canada
• Study type: Interventional

Clinical Trial Summary

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.

Description:

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 806
• Est. completion date: February 2012
• Est. primary completion date: February 2012
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Deep Venous Thrombosis
• Postphlebitic Syndrome
• Postthrombotic Syndrome
• Thrombosis
• Venous Thrombosis

Intervention

Device:
• Knee-length, graduated elastic compression stocking
Worn daily for 2 years, 30-40 mm Hg
• Knee-length, placebo stocking
Worn daily for two years

Locations

Country	Name	City	State
Canada	QE II Health Sciences Centre	Halifax	Nova Scotia
Canada	Hamilton Health Sciences - Chedoke Division	Hamilton	Ontario
Canada	Hamilton Health Sciences - General Hospital	Hamilton	Ontario
Canada	Hamilton Health Sciences - Henderson General Hospital	Hamilton	Ontario
Canada	Hamilton Health Sciences - McMaster University Medical Centre	Hamilton	Ontario
Canada	St. Joseph's Healthcare Hamilton	Hamilton	Ontario
Canada	London Health Sciences Centre	London	Ontario
Canada	Centre Hospitalier Pierre-Boucher	Longueuil	Quebec
Canada	Centre Hospitalier de l'Université de Montréal - Hôpital Hôtel-Dieu	Montreal	Quebec
Canada	Centre Hospitalier de l'Université de Montréal - Hôpital Notre-Dame	Montreal	Quebec
Canada	Hôpital du Sacré-Coeur de Montréal	Montreal	Quebec
Canada	Hôpital Maisonneuve-Rosemont	Montreal	Quebec
Canada	Montreal General Hospital - McGill University Health Centre	Montreal	Quebec
Canada	Royal Victoria Hospital - McGill University Health Centre	Montreal	Quebec
Canada	Sir Mortimer B. Davis - Jewish General Hospital	Montreal	Quebec
Canada	St. Mary's Hospital Center	Montreal	Quebec
Canada	The Ottawa Hospital, Civic Campus	Ottawa	Ontario
Canada	Centre hospitalier affilié universitaire de Québec, Hôpital de l'Enfant-Jésus	Quebec City	Quebec
Canada	Sunnybrook & Women's College Health Sciences Centre	Toronto	Ontario
Canada	University Health Network - Toronto General Hospital	Toronto	Ontario
Canada	Victoria Heart Institute Foundation	Victoria	British Columbia
Canada	St. Boniface General Hospital	Winnipeg	Manitoba
United States	Henry Ford Health Systerm	Detroit	Michigan
United States	Duke University Medical Center	Durham	North Carolina
United States	Oklahoma University Health Sciences Center	Oklahoma City	Oklahoma

Sponsors (3)

Lead Sponsor	Collaborator
Sir Mortimer B. Davis - Jewish General Hospital	Canadian Institutes of Health Research (CIHR), Sigvaris Corporation

Countries where clinical trial is conducted

United States,  Canada, 

References & Publications (2)

Kahn SR, Shapiro S, Wells PS, Rodger MA, Kovacs MJ, Anderson DR, Tagalakis V, Houweling AH, Ducruet T, Holcroft C, Johri M, Solymoss S, Miron MJ, Yeo E, Smith R, Schulman S, Kassis J, Kearon C, Chagnon I, Wong T, Demers C, Hanmiah R, Kaatz S, Selby R, Rat — View Citation

Kahn SR, Shbaklo H, Shapiro S, Wells PS, Kovacs MJ, Rodger MA, Anderson DR, Ginsberg JS, Johri M, Tagalakis V; SOX Trial Investigators. Effectiveness of compression stockings to prevent the post-thrombotic syndrome (the SOX Trial and Bio-SOX biomarker substudy): a randomized controlled trial. BMC Cardiovasc Disord. 2007 Jul 24;7:21. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Incidence of Post-thrombotic Syndrome (PTS)		During 2-year follow up	No
Secondary	Severity of PTS, Including Incidence of Venous Ulcer	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.	6-24 months.	No
Secondary	Incidence of Objectively Confirmed Recurrent Venous Thromboembolism (VTE), Death From VTE and Major Bleeding		During 2-year follow up	Yes
Secondary	Quality of Life	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.	24 months	No

External Links

•   Biomarker Sub Study of the Compression Stockings to Prevent the Post-Thrombotic Syndrome (SOX) Trial (Bio-SOX)