PubMed: 29339691, 2-s2.0-85040780102, Objective: A wide gap exists between dyslipidemia guidelines and their implementation in the real world, which is primarily attributed to physician and patient compliance. The aim of this study is to determine physician and patient adherence to dyslipidemia guidelines and various influential factors. Methods: The Evaluation of Perceptions, Knowledge, and Compliance with the Guidelines in Real Life Practice: A Survey on the Under-treatment of Hypercholesterolemia (EPHESUS) trial (ClinicalTrials.gov number NCT02608645) will be an observational, multicenter, non-interventional study. The study targets enrollment of 2000 patients from 50 locations across Turkey. All of the data will be collected in a single visit and current clinical practice will be evaluated. A cross-sectional survey of public perception and knowledge of cholesterol treatment among Turkish adults will be performed. All consecutive patients admitted to cardiology clinics who are in the secondary prevention group (coronary heart disease, peripheral artery disease, atherosclerotic cerebrovascular disease) and who are in the high-risk primary prevention group (type 2 diabetes mellitus with no prior known coronary heart disease; patients who had markedly elevated single risk factors, in particular, cholesterol >8 mmol/L [>310 mg/dL], blood pressure ?180/110 mmHg, a calculated Systematic Coronary Risk Evaluation [SCORE] ?5%, or