'Query Tool' is the main panel in which users construct, refine, and submit i2b2 queries.
Initially the Query Tool shows three Groups to the users, but only one (the first one) is active. Users are to add criteria via drag-and-drop to the Groups to construct their queries. A number of potential i2b2 objects can be added to the Groups. They include ontology terms, previous queries, results of previous queries, and items from the Workplace.
The Navigate/Find Terms panel contains all available ontologies. Users can browse or use its search functionalities to find a certain terms. After identifying the terms users wish to query for, they can drag and drop them into the Groups.
The Previous Queries panel lists all previously submitted queries. Users may drag and drop a previous query into a Group. When a new query contains a previous query is executed, i2b2 will run the previous query first. The previous query's results are then used in conjunction with the other terms in the new query to obtain the final results. In this sense, a previous query in a query can be thought of as a sub-query.
For each previous query in the Previous Queries panel, its results such as individual patients or patient sets can also be dropped into the Groups.
Workplace is a place where users can put any i2b2 objects such as ontology terms, previous queries, patient sets, etc. they wish to save for later. Users can then drag these saved objects into the query Groups. In addition,
Order of Precedents
(e.g. "Find patients who have a systolic blood pressure reading greater than 130 mm Hg")