Study to Gather Information to What Extent Patients Follow the Treatment Regimen of Low-dose Aspirin for Primary and Secondary Prevention of Diseases of the Heart and Blood Vessels

Persistence and Adherence to Low-Dose Aspirin for Primary and Secondary Prevention of Cardiovascular DiseasE Using OHDSI

This study aims to gather information to what extent patients follow the treatment regimen of low-dose aspirin for primary and secondary prevention of diseases of the heart and blood vessels. Researcher will collect information about the percentage of time a patient has access to the medication, how long patients continue with the medication and of the proportion of patients who switch from dual-antiplatelet therapy (including low-dose aspirin) to a single antiplatelet therapy. The study will make use of secondary healthcare data sources converted in to Observational Medical Outcomes Partnership (OMOP) common data model within the Observational Health Data Sciences and Informatics (OHDSI) network.

Inclusion Criteria:

• Aged ≥18 years

• Patients will be selected if they have at least two prescriptions for low-dose aspirin (75-100 mg) between 2008 and 2018 for either:

  • Primary prevention of CVD This is defined as patients who have no history of CVD any time prior to initiation of low-dose aspirin treatment are presumed to use for primary CVD prevention
  • Secondary prevention of CVD This is defined as patients who have a history of CVD any time prior to initiation of low-dose aspirin treatment

• Patients with at least two prescriptions of low-dose aspirin with a dosage of 75-100mg within the first year of the index date.

• Restricted to patients with observation for at least 12 months before and 12 after the index date.

Exclusion Criteria:

- Prescription of low-dose aspirin in 12 months before the index date.