part of HADES
This document is a DRAFT guidance.
Note (caution): Logic Description are succinct ideas
used by phenotyper to convey the structure of their implementation. It
only applies for rule-based phenotyping using OHDSI tools like
Atlas or CapR.
- Logic description is required for peer review. Logic description
will be captured in the notes section of the Phenotype library.
- We recommend you write a logic description prior to beginning
phenotyping. It is written after clinical description is complete.
- The logic description would follow the structure of building cohort
definitions in Atlas, but without the full details. It is expected to
- We have experienced that taking this approach improves the quality
of your cohort definitions, reduces bugs in your cohort definition and
allows to build cohort definitions collaboratively.
- It is also a required element for peer-review, as a logic
description indicates to the peer reviewers that the rules implemented
in Atlas are deliberate design choices and not an unintentional accident
- This is a semi-formal representation. So usage of key words is
Entry event criteria - what allows the person to enter the
cohort. The Presentation, Assessment and Plan components of the Clinical
Description often provide helpful guidance for what observed events may
allow for cohort entry.
Inclusion rule - what additional rules determine which
entry events qualify for the cohort. The dis-qualifier component of the
Clinical Description may provide guidance creating inclusion rules to
eliminate ‘false positive’ events, and elements from Presentation,
Assessment, Plan and Strengtheners may be used to further increase
Exit criteria - What constitutes the end of an episode for
a person. The Prognosis section of the Clinical Description can provide
guidance on how long a disease episode lasts.