<qa>  What is the dependent variable of the study?The aim of the study is to compare clinical outcomes between the different treatment strategies frequency of events and time to first event. The influence of alternative treatment strategies is measured on the basis of three different methodological approaches: unadjusted comparison of event council and time to first event between the defined patient groups; matched-pair comparison propensity score matching between the different groups of patients treatment strategies and multivariate analysis using time to event Cox proportional hazards model as the dependent variable. 