Study design
The design of the ASSOS trial has already been described in detail (13). In brief, the ASSOS study was an observational and cross-sectional national registry study. The study was performed by 30 cardiologists in 14 different cities and the data was collected during a routine ambulatory visit from March 1, 2018, to June 31, 2018. All consecutive patients admitted to the outpatient cardiology clinics who have been prescribed aspirin, irrespective of the indication for use, were included. The study did not stipulate any diagnostic or treatment procedures. The study was approved by the Institutional Review Board of Local Ethics Committee (Muğla Sıtkı Kocman University Faculty of Medicine) and registered at ClinicalTrials.gov (NCT03387384).
The number of patients was proportional to the population of each 7 regions of Turkey. Patients aged 18 years or older at the time of enrollment, willing to participate and provided written consent, and treated with aspirin (75–100 mg) within the last 30 days were included. Pregnant patients, minors <18 years, and patients with a mental disorder were excluded.
Patients were divided into two groups according to the use of aspirin; primary prevention group patients were defined as participants who did not have any clinically apparent CVD and secondary prevention group patients were the participants who had documented CVD manifested by fatal or non-fatal myocardial infarction, angina pectoris, aortic atherosclerosis and thoracic or abdominal aortic aneurysm, peripheral artery disease manifested by intermittent claudication and critical limb ischemia, and cerebrovascular disease manifested by fatal or non-fatal stroke and transient ischemic attack.