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

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.