The last years there has been an interest to study the comparative effectiveness of OD vs. SP (Secondary Prophylaxis) treatment strategies so as to create an evidence based platform to guide both clinical decision making and quantify the economic aspects of each treatment alternative. In Greece relevant information is lacking, thus it is imperative to study how patients on different treatment strategies are managed in a real-life setting in Greece, including the main factors associated with increased health care utilization, clinical success and patient well being.