Computerized Clinical Decision Support Systems (CDSS) are implemented in hospitals to improve prevention of Venous Thromboembolisms (VTE). A physician-driven review was conducted to assess extent of patient outcome effects of recently published CDSS studies. To facilitate future re-implementations within existing hospital information systems, input variables of included systems were extracted, standardized and annotated with semantic codes. Item category coverages of the different systems were then compared. 73% of studies showed positive medical effect. Of these, 53% showed strong positive medical effect by reducing incidence of deep vein thromboses and pulmonary embolisms. Outcome-improving systems tend to cover more item categories. A broad set of clinically relevant input variables should be taken into account or reused from the electronic health record if considering CDSS implementation. Input data models are provided for download in different standardized formats. Site-specific organizational factors that determine how systems are introduced, implemented and tested are also crucial for success.