Greetings all,
As a one-off, I have decided to publish a small indication of where GEHR is going with respect to querying.
Many people ask how GEHR supports queries, and how is data extracted from the EHR. Not much documentation has been produced on this subject to date, because the querying system for GEHR is quite different from other systems, due to the use of archetypes.
However, to give an idea of how one category of query will work, I have included an example below. The technical basis for queries with archetypes is that: every archetype has an "archetype query profile", which is a sort of inverted list of all possible paths in the archetype, keyed by leaf node name. For example, the query profile for a blood pressure observation archetype is as follows:
------ Archetype Query Profile: gehr.cont-observe.blood_pressure.v1
------------------
Diastolic:
|"blood pressure"|"Diastolic"
Systolic:
|"blood pressure"|"Systolic"
blood pressure:
|"blood pressure"
Here, the first column contains tag names which applications are likely to want to search for in patient data. The path fragments on the right hand side can be attached to the paths for higher up archetypes (e.g. which ever archetype was used to construct the organisers containing the BP), and submitted to the query engine, in order to extract a particular datum from the record. This list was derived automatically from the blodd pressure archetype.
Here are a couple more examples:
-------- Archetype Query Profile: gehr.org.soap.v1 ------------------
Plan:
/"SOAP Headings"/"Problem"/"Plan"
Objective:
/"SOAP Headings"/"Problem"/"Objective"
Subjective:
/"SOAP Headings"/"Problem"/"Subjective"
Assessment:
/"SOAP Headings"/"Problem"/"Assessment"
SOAP Headings:
/"SOAP Headings"
Problem:
/"SOAP Headings"/"Problem"
---- Archetype Query Profile: gehr.cont-subj.allergies.v1 ------------------
Date:
|"Allergies"|"Date"
Code:
|"Allergies"|"Code"
Code set:
|"Allergies"|"Code"|"Code set"
Allergies:
|"Allergies"
Substance name:
|"Allergies"|"Substance name"
Drug code:
|"Allergies"|"Code"|"Drug code"
Type:
|"Allergies"|"Type"
Comment:
|"Allergies"|"Comment"
Scope:
|"Allergies"|"Scope"
Notice that organiser-level archetype paths are "/" delimited, content paths are "|" delimited.
For people wishing to discuss querying, please use mailto:[EMAIL PROTECTED] (or else the open source discussion list).To subscribe to gehr-discuss, go to http://www.egroups.com/group/gehr-discuss
- thomas beale
(for the GEHR team)
