Description of Patients With Acute Venous Thromboembolism in the UK's Clinical Practice Research Datalink Linked With Hospital Episode Statistics Dataset (CPRD-HES)

Study Overview
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Brief Summary
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This study will utilize a retrospective cohort design. Using the Clinical Practice Research Datalink (CPRD) linked with Hospital Episode Statistics (HES) datasets, all patients with a record of VTE diagnosis between 1 April, 2008 and 31 March, 2013 will be identified and followed from the occurrence of VTE (index date) to the first of 24 months after the index date, end of the study period, leaving the database, or death.

Official Title
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Anticoagulation Treatment Patterns and Persistence After Acute Venous Thromboembolism in the UK in Routine Clinical Practice: A Retrospective Database Study of the Clinical Practice Research Datalink and the Hospital Episode Statistics Dataset

Conditions
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Venous Thromboembolism

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: VTE events will be included if: they are identified by at least one Read code diagnosis of acute VTE in the CPRD, or one ICD-10 code of VTE in the HES database, during the study period; and they occurred in patients ≥ 18 years old at time of VTE occurrence; and CPRD acceptability quality criteria are present Exclusion Criteria: VTE events will be excluded if: Patients have fewer than 12 months of computerized data available prior to VTE occurrence. The date of start of computerized records will be the latter of the patient's date of current registration with the practice or the practice's Up-to-Standard (UTS) date (date from which practice data is of research quality)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Population with condition and with exposure<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Anticoagulation treatment patterns for patients following acute Venous Thromboembolism (VTE) based on all VTE events that occur during the study period | Anticoagulation treatment pattern includes type of anticoagulant (AC), duration of AC treatment, switching between ACs and switching from AC to aspirin or other antiplatelet agents (APA). | up to 24 months following VTE occurrence | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Demographic characteristics (age, gender) of patients with acute VTE |  | up to 24 months following VTE occurrence | 
| Clinical characteristics (comorbidities, concomitant treatments, medical and surgical history) of patients with acute VTE |  | up to 24 months following VTE occurrence | 
| Rates of unplanned (emergency) hospital admission, major surgery, major bleeding, and VTE recurrence |  | up to 24 months following VTE occurrence | 
| Baseline demographic and clinical characteristics associated with the duration of AC treatment after VTE |  | up to 24 months following VTE occurrence | 
| Baseline demographic and clinical characteristics associated with novel oral anticoagulant (NOAC) treatment compared with vitamin K antagonist (VKA) treatment following VTE |  | up to 24 months following VTE occurrence |