Epidemiological Study on the Safety of Aspirin in The Health Improvement Network (THIN)

Study Overview
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Brief Summary
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To investigate the risk of major bleeding (including gastrointestinal and intracranial bleeding episodes) among new users of low-dose acetylsalicylic acid (ASA) in clinical practice

Detailed Description
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These will be based on population-based cohorts using data from a primary care database in the UK: The Health Improvement Network (THIN) and will serve to make a clinically meaningful benefit-risk assessment regarding major bleeding consequences of ASA exposure in general population.

Official Title
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A Pharmacoepidemiological Study on the Risk of Bleeding in New Users of Low-dose Aspirin (ASA) in The Health Improvement Network (THIN), UK

Conditions
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Secondary Prevention, Stroke, Ischemic Heart Disease, Coronary Heart Disease

Intervention / Treatment
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* Drug: Acetylsalicylic Acid (Aspirin, BAYE4465)
* Drug: Clopidogrel, Oral Anticoagulants, NSAIDs and SSRIs


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 40-84 years Enrolled with the Primary Care Physician (PCP) for at least 2 years, To have a history of computerized prescriptions for at least 1 year prior To have at least one encounter/visit recorded in the last three years Exclusion Criteria: To be exposed to low dose ASA before entering in the study Having a diagnosis of cancer before entering in the study Having a diagnosis of alcohol abuse before entering in the study Having a diagnosis of coagulopathies before entering in the study Having a diagnosis of esophageal varices before entering in the study Having a diagnosis of chronic liver disease before entering in the study

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 84 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 |
| --- | --- |
| Acetylsalicylic Acid<br>New users of low-dose Acetylsalicylic Acid (ASA) | Drug: Acetylsalicylic Acid (Aspirin, BAYE4465)<br>* Low-dose ASA for secondary prevention of cardiovascular events<br>|
| Other medications<br>Users of other medications such as clopidogrel, oral anticoagulants, non-steroidal anti-inflammatory drugs (NSAIDs) and selective serotonin reuptake inhibitors (SSRIs) | Drug: Clopidogrel, Oral Anticoagulants, NSAIDs and SSRIs<br>* Secondary prevention of cardiovascular events<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of Intracranial bleeding among new users of low-dose Acetylsalicylic acid (ASA). |  | Up to 13 years | 
| Incidence of Upper gastrointestinal bleeding among new users of low-dose ASA. |  | Up to 13 years | 
| Incidence of Lower gastrointestinal bleeding among new users of low-dose ASA |  | Up to 13 years | 
| Time to Intracranial bleeding among new users of low-dose ASA |  | Up to 13 years | 
| Time to Upper gastrointestinal bleeding among new users of low-dose ASA |  | Up to 13 years | 
| Time to Lower gastrointestinal bleeding among new users of low-dose ASA |  | Up to 13 years | 
| Relative risk of Intracranial bleeding among new users of low dose ASA | Relative risk is calculated as incident rate ratio produced by dividing the incidence rate of the outcome of interest in the exposed category by the incidence rate of the outcome of interest in the unexposed. | Up to 13 years | 
| Relative risk of Upper gastrointestinal bleeding among new users of low-dose ASA | Relative risk is calculated as incident rate ratio produced by dividing the incidence rate of the outcome of interest in the exposed category by the incidence rate of the outcome of interest in the unexposed. | Up to 13 years | 
| Relative risk of Lower gastrointestinal bleeding among new users of low-dose ASA | Relative risk is calculated as incident rate ratio produced by dividing the incidence rate of the outcome of interest in the exposed category by the incidence rate of the outcome of interest in the unexposed. | Up to 13 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Relative risk of Intracranial bleeding associated with use of other medications. | Relative risk is calculated as incident rate ratio produced by dividing the incidence rate of the outcome of interest in the exposed category by the incidence rate of the outcome of interest in the unexposed.To estimate relative risk in users of other medications such as clopidogrel,oral anticoagulants, non-steroidal anti-inflammatory drugs (NSAIDs) and selective serotonin reuptake inhibitors (SSRIs), independently from use of low-dose ASA and concomitantly | Up to 13 years | 
| Relative risk of Upper gastrointestinal bleeding associated with use of other medications | Relative risk is calculated as incident rate ratio produced by dividing the incidence rate of the outcome of interest in the exposed category by the incidence rate of the outcome of interest in the unexposed.To estimate relative risk in users of other medications such as clopidogrel,oral anticoagulants, non-steroidal anti-inflammatory drugs (NSAIDs) and selective serotonin reuptake inhibitors (SSRIs), independently from use of low-dose ASA and concomitantly | Up to 13 years | 
| Relative risk of Lower gastrointestinal bleeding associated with use of other medications. | Relative risk is calculated as incident rate ratio produced by dividing the incidence rate of the outcome of interest in the exposed category by the incidence rate of the outcome of interest in the unexposed.To estimate relative risk in users of other medications such as clopidogrel,oral anticoagulants, non-steroidal anti-inflammatory drugs (NSAIDs) and selective serotonin reuptake inhibitors (SSRIs), independently from use of low-dose ASA and concomitantly | Up to 13 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Low-dose Acetylsalicylic Acid,, Bleeding,, The Health Improvement Network (THIN),, Cardiovascular, Secondary prevention of cardiovascular events