Figure 7
From: Is OpenSDE an alternative for dedicated medical research databases? An example in coronary surgery
Design of query5 in the original SDETreeNode table. Attribute PickListItem represents a categorical value. This query filters for values representing surgery rooms. Attribute TreeNodeName in table SDEDomainModelItem contains the name of a node, and is needed to filter SDETreeNode for "in hospital complications". Attribute PresenceState represents whether a node has been entered as present or absent. The inner join of table SDETreeNode is needed to combine the proper rows (such that "in hospital complications" and surgery room value were part of the same registration).