Tuesday, November 11, 2008

Semantic Interoperability: Adverse Events

When reviewing the Bridg Release 2.0 Static Elements report.RTF I did look in a bit of detail at the adverse event model.

Here's a summary:

The AdverseEvent
class is decribed as having the following connections and attributes

Connections

  • Association link from class PerformedProductInvestigation

  • Association link from class Subject

  • Association link to class AEOutcomeAssessmentRelationship
  • Association link to class AECausalityAssessmentRelationship
  • Association link to class AEActionTakenRelationship
  • Generalization link to class PerformedObservationResult

  • Association link from class PerformedProductInvestigation

  • Generalization of PerformedActivity adding an evaluationMethodCode attribute; PerformedActivity captures the duration of the activity

  • Association link from class Subject -- the clinical subject (An entity of interest, either biological or otherwise.)

  • Association link to class AEOutcomeAssessmentRelationship
    links the AE to an observation
    For example, recovered/resolved, recovering/resolving, not recovered/not resolved, recovered/resolved with
    sequelae, fatal or unknown

  • Association link to class AECausalityAssessmentRelationship
    links the ae to an observation.
    For example, when an adverse event occurs, a physician may evaluate interventions that may have caused the
    adverse event.

  • Association link to class AEActionTakenRelationship.
    Specifies the link between an adverse event and the steps performed to address it.
    For example, study dose reduced, protocol treatment change, etc.

  • Generalization link to class PerformedObservationResult
    links all observations/protocol deviations etc together with a report.


The AE itself has the attributes:
  • gradeCode

  • severityCode
  • seriousnessCode

  • occurrencePatternCode
  • unexpectedReasonCode

  • expectedIndicator

  • highlightedIndicator
  • hospitalizationRequiredIndicator

  • onsetDate
  • resolutionDate


The end result is a structure that has a formal relationship that is well thought out, should cover all situations and permits systems to interoperate.

In my mind, this is not the same as assuring semantic interoperabillity. For semantic interoperability to really occur, the grade codes must be comparable across sites, hospitalization criteria must be identical (or at least commensurable) etc.. Achieving this comparability requires continuing education and harmonization efforts, constant feedback of metrics to practitioners etc.. It therefore represents a much higher bar.

This is not in any way a criticism of BRIDG. You need something like BRIDG -- a well vetted industry standard -- to be even be able to begin such an attempt. However, true semantic interoperability involves not only the structure of the data, but the data itself.

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