A pharmacoepidemiological study on the risk of bleeding in new users of low-dose aspirin (ASA) in The Health Improvement Network (THIN), UK (EPISAT)

Study type

• Study topic:
  Disease /health condition

  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness
• Data collection methods:
  Secondary use of data

Non-interventional study

• Non-interventional study design:
  Case-control

  Cohort

Study drug and medical condition

• Anatomical Therapeutic Chemical (ATC) code:
  (B01AC) Platelet aggregation inhibitors excl. heparin

  Platelet aggregation inhibitors excl. heparin
• Medical condition to be studied:
  Haemorrhage intracranial

  Upper gastrointestinal haemorrhage

  Lower gastrointestinal haemorrhage

Population studied

• Short description of the study population:
  Individuals will be required to be aged between 40-84 years, to be enrolled with the 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 and to be free of ASA, cancer, alcohol abuse, coagulopathies, esophageal varices and chronic liver disease to become a member of the study population. The date an individual met all these criteria will be considered as entry date. Individuals will be followed up from entry date up to one of the following endpoints, whichever came first: first prescription of low-dose ASA, diagnosis of cancer, alcohol abuse, coagulopathies, oesophageal varices, chronic liver disease, aged 85 years, death or end of the study period.; ; Inclusion criteria to qualify as member of the study population; - Aged 40-84 years; - Enrolled with the 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 qualify as member of the study population; - 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
• Age groups:
  • Adult and elderly population (≥18 years)

    • Adults (18 to < 65 years)

      • Adults (18 to < 46 years)
      • Adults (46 to < 65 years)
    • Elderly (≥ 65 years)

      • Adults (65 to < 75 years)
      • Adults (75 to < 85 years)
• Estimated number of subjects:
  400000

Study design details

• Main study objective:
  The main objective of this study is 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.
• Outcomes:
  -Incidence of Intracranial bleeding, Upper gastrointestinal(UG) bleeding and Lower gastrointestinal(LG) bleeding among new users of low-dose Acetylsalicylic acid(ASA) -Time to Intracranial bleeding, UG bleeding and LG bleeding among new users of low-dose ASA -Relative risk of Intracranial bleeding, UG bleeding and LG bleeding among new users of low-dose ASA, -Relative risk of Intracranial bleeding associated with use of other medications -Relative risk of Upper gastrointestinal bleeding associated with use of other medications -Relative risk of Lower gastrointestinal bleeding associated with use of other medications
• Data analysis plan:
  Incidence, time to event, relative risk (overall and in age and sex-specific, duration and dose response.