This study is conducted in a cohort of low dose aspirin (ASA) users previously ascertained .The aims of the post hoc analyses are:

To estimate the one year risk of discontinuation of use of low-dose ASA associated to PPI concomitant use versus non-use, crude and adjusted by confounding.

To estimate the one year risk of discontinuation of use of low-dose ASA associated to PPI concomitant use stratified by age and sex.

To evaluate other predictors of discontinuation of low-dose ASA during the first year of ASA therapy.

Assessment of low-dose ASA discontinuation risk associated with concomitant PPI use during the first year of ASA therapy for secondary prevention

Inclusion Criteria:

• Patients aged 50-84 years in 2000-2007.
• Patients with first prescription of low dose ASA ( see study population description).
• Patients were required to have been enrolled with their primary care practitioner (PCP) for at least 2 years and to have a computerized prescription history of at least 1 year before the start of the study.

Exclusion Criteria:

• Patients aged below age 50 and 85 years and above ( see study population description).
• Patients with a diagnosis of cancer, alcohol abuse or alcohol-related disease.
• Incomplete data recording in THIN.

This is a pharmacoepidemiology study using data from The Health Improvement Network (THIN) primary care database in the UK. Patients aged 50-84 years with evidence of ischemic heart disease or cerebrovascular disease, who were new users of low-dose ASA (75-300 mg/day) and who had received at least two low-dose ASA prescriptions for the secondary prevention of cardiovascular disease or cerebrovascular disease between 2000 and 2007 were identified from THIN. .