FHIR Chat · Mapping CDA to FHIR

Stream: implementers

Topic: Mapping CDA to FHIR

Ramandeep Dhanoa (Jun 27 2019 at 20:01):

Hello, we are working on mapping of Medical Imaging CDA standard (Level 3 ) to FHIR, and we need some clarification regarding few concepts:

Diagnosis: We need to map 2 types of diagnosis: Primary and Differential (First diagnosis is the primary, all others are differential) - At high level I think diagnosis is mapping to Condition Resource, and to differentiate between primary and secondary use reference to the encounter resource - Encounter.diagnosis.use and Encounter.diagnosis.rank (both the elements to depict the type of diagnosis and ranking will be helpful to differentiate which diagnosis has more importance). However, I see the value set of Encounter.diagnosis.use are very different (it has Preferred type):
AD Admission diagnosis
DD Discharge diagnosis
CC Chief complaint
CM Comorbidity diagnosis
pre-op pre-op diagnosis
post-op post-op diagnosis
billing Billing
Do you think Primary and Differential type will fit here? Please let me know what are your thoughts on this?

Ramandeep Dhanoa (Jun 27 2019 at 20:18):

@Lloyd McKenzie I guess we are using 'Differential' term to indicate the secondary diagnosis (I will clarify this with further with lab team). Sorry for the confusion, so for example if radiologist concluded that a patient has a primary diagnosis and few of the secondary diagnosis, I guess encounter.diagnosis.rank will cover this concept (with primary diagnosis ranked as 1 and subsequent rankings for the secondary diagnosis..)

Lloyd McKenzie (Jun 27 2019 at 20:25):

Right. Rank lets you distinguish primary from secondary. The notion of differential is a distinct concept. A differential diagnosis can be the primary diagnosis for an encounter. Differential just indicates that it's a candidate diagnosis that hasn't yet been ruled out or confirmed.

Ramandeep Dhanoa (Jun 27 2019 at 20:45):

So, I am just trying to envision how diagnosis will look like in the condition resource:

Condition Resource:

identifier
.
.
.
Reference to encounter - Primary Diagnosis (Rank = 1)
Reference to encounter - Secondary Diagnosis (Rank = 2)
Reference to encounter - Secondary Diagnosis (Rank = 3)
.
.

Will there be 3 different references to the Encounter resource? or 1 reference to encounter with 3 sets of diagnosis?

Other questions that are coming to mind is how we will be handling negations in diagnosis, for example if radiologists accidentally entered a diagnosis and wants to refute it (but then if verificationStatus is set to 'refuted' then all 3 diagnosis becomes 'refuted'?).

Lloyd McKenzie (Jun 27 2019 at 22:13):

Condition won't reference Encounter. Encounter will reference Condition. A Condition might be a 'primary' diagnosis for encounter A while it's a 'secondary' diagnosis for Encounter B.