In CRITISCH registry, randomization or blinding is not feasible, because optimized standard care will be performed as established at each participating centre (best medical treatment). Data storage, validation, monitoring, update, backup and analysis will be performed centrally following established procedures. Web-based software will be used to develop a data model representing the data structure. The data validation will include standard data validation techniques such as the manual review of selected variables and the routine check of missing and outlying data points. Regional staff will be instructed and supervised by study nurse, who will perform the study monitoring. Assessment of relevant prognostic factors during the statistical analysis will prevent biased results due to the non-randomized design and the potential structural inequality.