The Risk of Venous Thromboembolism in Systemic Inflammatory Disorders: a United Kingdom (UK) Matched Cohort Study

May 27, 2025 updated by: Momentum Data

The Risk of Venous Thromboembolism in Systemic Inflammatory Disorders: a UK Matched Cohort Study

Blood clots occurring in the legs and in the lungs are relatively common; they occur in around 3 in a 1000 people per year. They can cause disability and are also potentially life threatening. When a clot occurs in the legs it is called a deep vein thrombosis or DVT. When they occur in the lungs they are called a pulmonary embolism or PE. The risk for DVT and PE is higher in people with conditions which cause inflammation. The most common of these are inflammatory bowel disease (ulcerative colitis and Crohn's disease), rheumatoid arthritis, and psoriatic arthritis (a condition comprised of psoriasis and joint inflammation).

What is not known is how much higher the risk of DVT and PE is in these groups compared with people without inflammatory disease, and what causes the excess risk in these people. This study aims to assess the measure the exact increase in risk for DVT and PE in people with these inflammatory conditions and to identify which risk factors are most strongly associated with the increased risk. These data should help with an understand the causes of blood clot risk in these inflammatory conditions and in identify targets for reducing risk.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Background

Venous thromboembolism (VTE), comprising pulmonary embolism (PE) and deep vein thrombosis (DVT), are common and associated with significant morbidity and mortality. VTE risk is higher in chronic inflammatory conditions including inflammatory bowel disease (IBD) and rheumatoid arthritis (RA) compared to the general population. Evidence for differential VTE risk in other inflammatory diseases, notably psoriatic arthritis (PsA) and vasculitis, is more limited. Risk factors for VTE have been described in the general population, but there has been little interrogation of VTE risk factors for individuals with chronic inflammatory conditions and their association with subsequent VTE.

Objective

This study aims to describe the prevalence of VTE risk and risk factors in individuals with systemic inflammatory disorders in a contemporary real-world population, by disease type (IBD, RA, and PsA) and relative to a control population without systemic inflammatory disease. In the same cohorts a further comparison will be performed of the influence of VTE risk factors on risk of VTE events in individuals with systemic inflammatory disorders.

Method

A retrospective cohort study will be performed to compare VTE risk and VTE risk factors in adults with IBD, RA, and PsA and matched controls between January 1, 1998 and January 1, 2018, within the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) network. In the cohorts with and without inflammatory conditions estimate will be determined for the risk of VTE overall, and for PE and DVT separately, using unadjusted Cox proportional hazards models, stratified by matched set (exposed cohort versus unexposed cohort), to provide overall hazard ratios for the association with each outcome. Models will be subsequently adjusted for sociodemographic and clinical and VTE risk factors in multivariable analysis to explore potentially important associations with VTE. The same analyses for each autoimmune condition will be repeated separately. Prespecified sensitivity analyses will be performed to explore the robustness of any potential associations.

Study Type

Observational

Enrollment (Actual)

266890

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

The exposed cohort includes all individuals with an existing or incident diagnosis of IBD, RA or PsA (systemic inflammatory diseases) in the RCGP RSC over the study period. IBD, RA or PsA will be identified using Read diagnostic codes previously validated in UK primary care studies.

The matched unexposed cohort will be defined by matching individuals in the exposed cohort with individuals never diagnosed with a systemic inflammatory disease either prior to or during the study period by age and sex. Unexposed individuals require at least 1 year of follow-up when matched to minimize the risk they had a non-recorded existing diagnosis of a systemic inflammatory disease of interest. Follow-up for each matched individual will begin at the start of follow-up of their matched counterpart.

Description

Inclusion Criteria:

  • Adult patients (aged ≥18) contributing to RCGP RCS primary care database between January 1, 1998 and January 1, 2018, will be eligible for inclusion

Exclusion Criteria:

  • People with IBD which cannot be classified or is not ulcerative colitis or Crohn's disease will be excluded.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
People with inflammatory bowel disease
All individuals with an existing or incident diagnosis of IBD during the study period
Other: No intervention
A observation of outcomes in usual practice
People with rheumatoid arthritis
All individuals with an existing or incident diagnosis of RA during the study period
Other: No intervention
A observation of outcomes in usual practice
People with psoriatic arthritis
All individuals with an existing or incident diagnosis of IBD during the study period
Other: No intervention
A observation of outcomes in usual practice
Controls
Age, gender and primary care practice matched individuals without an existing or incident diagnosis of IBD, RA, or PsA during the study period
Other: No intervention
A observation of outcomes in usual practice

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Risk of Venous Thromboembolism (VTE)
Time Frame: A 20 year analysis period (1999-2018 inclusive)
Number of participants with systemic inflammatory disorders developing VTE (a composite of pulmonary embolism (PE) and deep vein thrombosis (DVT)) compared to population controls.
A 20 year analysis period (1999-2018 inclusive)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Risk of Pulmonary Embolism (PE)
Time Frame: A 20 year analysis period (1999-2018 inclusive)
Number of participants with systemic inflammatory disorders developing PE compared to population controls.
A 20 year analysis period (1999-2018 inclusive)
Risk of Deep Vein Thrombosis (DVT)
Time Frame: A 20 year analysis period (1999-2018 inclusive)
Number of participants with systemic inflammatory disorders developing DVT compared to population controls.
A 20 year analysis period (1999-2018 inclusive)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Momentum Data

Collaborators

Pfizer
University of Surrey

Investigators

  • Principal Investigator: Andrew McGovern, MD, Momentum Data

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 1, 2019

Primary Completion (Actual)

August 1, 2019

Study Completion (Actual)

December 1, 2019

Study Registration Dates

First Submitted

January 17, 2019

First Submitted That Met QC Criteria

February 7, 2019

First Posted (Actual)

February 11, 2019

Study Record Updates

Last Update Posted (Actual)

June 11, 2025

Last Update Submitted That Met QC Criteria

May 27, 2025

Last Verified

May 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • P004

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Individual patient data is confidential but can be made available in an anonymised form to bone fide researchers subject to the required data protection training and other requirements. All data will remain behind a firewall and will only be available for access through a secured computer network.

IPD Sharing Time Frame

The data will be available subject to approval for two years after the study publication date.

IPD Sharing Access Criteria

Data sharing is subject to required data protection training and other requirements.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Rheumatoid Arthritis

Clinical Trials on No intervention

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Russia

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe