'Query Tool' is the main component through which users construct, refine, and submit i2b2 queries. Query construction is primarily based on drag-and-drop and selecting the appropriate options. This page describes the various operations and options of 'Query Tool' and how to use it in conjunction with other components. The Table of Content below offers links to quickly jump to relevant topics. In addition, a quick start video show the query process and to demonstrate the basic query-building features.

3.1 Quick Start Video

This video introduces the basic functionalities of the Query Tool through building a series of simple queries.

3.2 What is a Query?

An i2b2 Query is a request that contains users search criteria for patients stored in an i2b2 database. The query is sent to an i2b2 server, where the query is evaluated and the requested results are returned after some time. The i2b2 Webclient is a front-end interface that abstracts away the need for users to understand the technical underpinnings of the i2b2 system so that anyone can use it.

  i. Definition of a Query

  ii. Life Cycle of a Query

  iii. Results of a Query

      1) Patient Number is the default result

      2) Other Options are available (see ... )

      3) Detailed medical data are not part of the results the Query Tool can provide. Other steps are required.

3.3 Building a New Query

    i. Including Terms

       1) Dragging and Dropping

       2) Including a Previous Query

       3) Including a Query Result (Patient Set/ Patient)

       4) Including a Folder in Workplace

    ii. AND/OR Operators

       Order of Precedents

    iii. How to use a lab test (terms with values)

    iv. Run Query and Clear buttons

3.4 Resetting the Query Tool (Clear)

3.5 What Happens when a query gets queued?

3.6  Rerun a Previous Query

3.7 Advanced Query Options

    i.Output Options

        1) Patient Set

        2) Encounter Set

        3) Number of Patients

        4) Gender Patient Breakdown

        5) Vital Status Patient Breakdown

        6) Race Patient Breakdown

        7) Age Patient Breakdown

        8) Timeline

        9) Length of Stay Breakdown

        10) Top 20 Medications Breakdown

        12) Top 20 diagnoses Breakdown

        13) Inpatient and Outpatient Breakdown

    ii. Managing Groups

        1) Additional Groups

        2) Shifting Group Order

        3) Delete Groups

    iii. Specifying Constraints

        1) Date Constraints  (Panel-level and Term-level)

        2) Negation (Exclude)

        3) Occurrences

    iv. Value Constraints

    v. Modifiers

        1) What are they?

        2) Has Value Constraints like Labs

        3) How are they represented in Navigate/Find Terms

            - Modifier

            - Modifier Container

    vi. Query Timing

        1) Treat all groups independently (default)

        2) Select Groups occur in the same financial encounter

        3) Define sequence of events (Temporal Query)

            - Simple

            - Advanced

            - Some Concepts do not make sense here (Put them in the Population )

3.8 Example Queries

  i. Simple Query: "Finding patients with a diagnosis A or a diagnosis B or has lab test C."

  ii. Running a Previous Query

  iii. Temporal Query (Simple)

  iv.  How to find Patients with >1 diagnosis X OR >1 diagnosis Y  (Using nested queries)