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Difference between Condition Era and Condition Group Era

(Henrik John) #1


The CDM wiki defines a Condition Era as a span of time when a person is assumed to have a given condition by combining individual condition occurrences.

Next to that I came across the Condition Group Era, which in the FeatureExtraction vignette is defined as: one covariate per condition era rolled up to groups in the condition_era table […].

What is meant with rolled up to groups and how does it differ from the normal Condition Era?

(Chris Knoll) #2

The logic of the Condition Group Era is defined here: https://github.com/OHDSI/FeatureExtraction/blob/master/inst/sql/sql_server/DomainConceptGroup.sql#L24, but basically it creates a concept ‘rollup’ using the CDM concept_ancestor (with additional rules around min_levels_of_separation) to create a parent-child relationship for SNOMED clinical findings. Once this hierarchy is established, the individual condition eras are ‘grouped’ together under the ancestor of the condition concept found int he condition_era table. For example, ‘Psoriasis’ maybe be a parent of the different sub-types of ‘psoriasis’ that are found in condition era, so a person with different diagnosis sub-types of Psoriasis will be counted only once in the ‘Psoriasis’ group, while without this grouping, this person would contribute a count to each psoriasis sub-type the person was diagnosed with.

(Christian Reich) #3


Why wouldn’t we promote the Condition Group Era as a CDM artefact?