Compression stockings to prevent post-thrombotic syndrome: the SOX trial

ISRCTN	ISRCTN71334751
DOI	https://doi.org/10.1186/ISRCTN71334751
ClinicalTrials.gov (NCT)	NCT00143598
Protocol serial number	MCT-63142
Sponsor	Sir Mortimer B. Davis Jewish General Hospital-Mtl (Canada)
Funders	Canadian Institutes of Health Research, SIGVARIS Corp. (Canada)

Submission date: 01/09/2005
Registration date: 01/09/2005
Last edited: 10/11/2015

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Circulatory System

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Not provided at time of registration

Contact information

Dr Susan Rebecca Kahn
Scientific

Center for Clinical Epidemiology and Community Studies
SMBD Jewish General Hospital
3755 Cote Ste. Catherine Rm A-127
Montreal, Quebec
H3T 1E2
Canada

Phone	+1 (0)514 3408222 (4667)
Email	susan.kahn@mcgill.ca

Ms Susan Kahn
Public

SMBD Jewish General Hospital
3755 Cote Ste. Catherine Rm A-127
Montreal, Quebec
H3T 1E2
Canada

Phone	+1 (0)514 340 8222 ext. 4667
Email	susan.kahn@mcgill.ca

Study information

Primary study design	Interventional
Study design	Multicentre two-arm placebo randomised parallel device trial with study participant, study investigator, and outcome assessor blinded.
Secondary study design	Randomised controlled trial
Study type	Participant information sheet
Scientific title	Compression stockings to prevent post-thrombotic syndrome: a multicentre, two arm, placebo-controlled randomised parallel device trial
Study acronym	SOX
Study objectives	To determine whether Elastic Compression Stockings (ECS) used for two years are effective in preventing the Post-Thrombotic Syndrome (PTS) in patients with symptomatic proximal Deep Venous Thrombosis (DVT). Previous hypothesis: To determine whether Elastic Compression Stockings (ECS) used for two years, and celecoxib, a COX-II inhibitor, used for 30 days are effective in preventing the Post-Thrombotic Syndrome (PTS) in patients with symptomatic proximal Deep Venous Thrombosis (DVT). Sub -study registered with ClinicalTrials.gov: NCT01615705 - Biomarker Sub Study of the Compression Stockings to Prevent the Post-Thrombotic Syndrome (SOX) Trial (Bio-SOX) Sub -study registered with ClinicalTrials.gov: NCT01615692 - The 36-month Extension to Follow up Sub Study
Ethics approval(s)	1. Canada: The Research Ethics Committee of Sir Mortimer B Davis Jewish General Hospital, 30/07/2003. This ethics approval was amended on 27/01/2005 to take into account the removal of the celecoxib intervention and consequent protocol changes. 2. USA: The University of Oklahoma Health Sciences Center Institutional Review Board (USA), 31/07/2007, ref: 13513. All other centres subsequent to this in the USA will require full ethics approval before recruiting participants.
Health condition(s) or problem(s) studied	Deep vein thrombosis
Intervention	Current interventions (protocol updated in January 2005): 1. Experimental interventions: knee-length, 30 - 40 mmHg (Class II), graduated ECS worn on the DVT-affected leg daily, applied upon waking and removed upon retiring, beginning within a week (as soon as possible) after DVT diagnosis, and continued for two years 2. Control interventions: knee-length, inactive (i.e. no compression) stocking, identical in appearance to active ECS, worn on the DVT-affected leg daily, applied upon waking and removed upon retiring, beginning within a week (as soon as possible) after DVT diagnosis, and continued for two years Previous interventions: 1. Experimental interventions: 1.1. Knee-length, 30 - 40 mmHg (Class II), graduated ECS worn on the DVT-affected leg daily, applied upon waking and removed upon retiring, beginning within a week (as soon as possible) after DVT diagnosis, and continued for two years 1.2. Celecoxib, 200 mg orally (po) twice a day (BID), begun on the day of DVT diagnosis and continued for 30 days 2. Control interventions: 2.1. Knee-length, inactive (i.e. no compression) stocking, identical in appearance to active ECS, worn on the DVT-affected leg daily, applied upon waking and removed upon retiring, beginning within a week (as soon as possible) after DVT diagnosis, and continued for two years 2.2. Placebo, identical in appearance to celecoxib, one tablet po BID, begun on the day of DVT diagnosis and continued for 30 days
Intervention type	Other
Primary outcome measure(s)	Incidence of post-thrombotic syndrome (PTS) at two years
Key secondary outcome measure(s)	Current secondary outcome measures (protocol updated in January 2005): 1. Severity of PTS at two years follow up, including incidence of venous ulcer 2. Incidence of objectively confirmed recurrent VTE, and death from VTE, over two years 3. C-reactive protein at 30 days compared to baseline value 4. Quality of life over the two-year follow up 5. Cost-effectiveness Previous secondary outcome measures: 1. Severity of PTS at two years follow up, including incidence of venous ulcer 2. Incidence of objectively confirmed recurrent VTE, and death from VTE, over two years 3. Incidence of major bleeding or arterial thrombotic events during the first 60 days 4. C-reactive protein at 30 days compared to baseline value 5. Quality of life over the two-year follow up 6. Cost-effectiveness
Completion date	31/01/2012

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Sex	All
Target sample size at registration	800
Key inclusion criteria	Current inclusion criteria (protocol updated in August 2008): Consecutive patients aged greater than or equal to 18 years old, either sex, with a first, symptomatic, objectively confirmed proximal DVT diagnosed within the last 14 days (with or without concurrent distal DVT or Pulmonary Embolism [PE]) who have no contraindications to standard treatment with heparin and/or warfarin, and who provide informed consent to participate. Previous inclusion criteria (January 2005): Consecutive patients aged greater than or equal to 18 years old, either sex, with a first, symptomatic, objectively confirmed proximal DVT diagnosed within the last 10 days (with or without concurrent distal DVT or Pulmonary Embolism [PE]) who have no contraindications to standard treatment with heparin and/or warfarin, and who provide informed consent to participate. Initial inclusion criteria (January 2004): Consecutive patients with a first, symptomatic, objectively confirmed proximal DVT diagnosed within the last 72 hours (with or without concurrent distal DVT or Pulmonary Embolism [PE]) who have no contraindications to standard treatment with heparin and/or warfarin, and who provide informed consent to participate.
Key exclusion criteria	Current exclusion criteria (protocol updated in January 2005): 1. Contraindication to compression stockings 2. Limited lifespan (estimated less than six months) 3. Geographic inaccessibility preventing return for follow-up visits 4. Inability to apply stockings daily and unavailability of a caregiver to apply stockings daily 5. Treatment of acute DVT with thrombolytic agents Previous exclusion criteria: 1. Contraindication to compression stockings 2. Contraindication to celecoxib 3. History of warfarin, aspirin or Non-Steroidal Anti-Inflammatory Drug (NSAID)-associated major haemorrhagic event 4. Regular, daily use of NSAIDs 5. Inability/unwillingness to stop anti-platelet drugs for 30 days 6. Limited lifespan (estimated less than six months) 7. Geographic inaccessibility preventing return for follow-up visits 8. Inability to apply stockings daily and unavailability of a caregiver to apply stockings daily 9. Treatment of acute DVT with thrombolytic agents
Date of first enrolment	01/04/2003
Date of final enrolment	17/02/2010

Locations

Countries of recruitment

Canada
United States of America

Study participating centre

SMBD Jewish General Hospital

Montreal, Quebec
H3T 1E2
Canada

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary
IPD sharing plan

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article	results	08/03/2014		Yes	No
Results article	results	01/12/2014		Yes	No
Protocol article	protocol	24/07/2007		Yes	No
Basic results				No	No
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes

Editorial Notes

Please note that in 2005, the intervention using Celecoxib was removed from this trial due to reports of negative effects in a large colorectal cancer prevention clinical trial. Thus, the SOX Trial protocol was amended to take this into account. The most recent changes to the protocol were made to this trial record on the 10/06/2009.

Due to the removal of the Celecoxib intervention, the recruitment resumed in February 2005, and the overall trial end date has now been extended by one year to 30/12/2011 (amended 10/06/2009). The previous overall trial end date was 30/03/2008 (amended 13/05/2008).

As of 17/02/2010 this record has been updated to include an extended overall trial end date; the initial overall trial end date of this record was 30/12/2011. Please note that enrolment to this trial is now completed.