Alchemist / Critical Care

Documentation on the data exchange format for HIC Critical Care and the Alchemist ingestion pipeline.

Condition Era

A Condition Era is defined as a span of time when the Person is assumed to have a given condition.

Similar to Drug Eras, Condition Eras are chronological periods of Condition Occurrence. Combining individual Condition Occurrences into a single Condition Era serves two purposes:

  • It allows aggregation of chronic conditions that require frequent ongoing care, instead of treating each Condition Occurrence as an independent event.
  • It allows aggregation of multiple, closely timed doctor visits for the same Condition to avoid double-counting the Condition Occurrences.

For example, consider a Person who visits their Primary Care Physician (PCP) and who is referred to a specialist. At a later time, the Person visits the specialist, who confirms the PCP’s original diagnosis and provides the appropriate treatment to resolve the condition. These two independent doctor visits should be aggregated into one Condition Era.

Field Required Type FK Table Description
condition_era_id Yes bigint   A unique identifier for each Condition Era.
person_id Yes bigint PERSON A foreign key identifier to the Person who is experiencing the Condition during the Condition Era. The demographic details of that Person are stored in the PERSON table.
condition_concept_id Yes bigint CONCEPT A foreign key that refers to a standard Condition Concept identifier in the Standardized Vocabularies.
condition_era_start_date Yes date   The start date for the Condition Era constructed from the individual instances of Condition Occurrences. It is the start date of the very first chronologically recorded instance of the condition.
condition_era_end_date Yes date   The end date for the Condition Era constructed from the individual instances of Condition Occurrences. It is the end date of the final continuously recorded instance of the Condition.
condition_occurrence_count No integer   The number of individual Condition Occurrences used to construct the condition era.

Conventions

  • Condition Era records will be derived from the records in the CONDITION_OCCURRENCE table using a standardized algorithm.
  • Each Condition Era corresponds to one or many Condition Occurrence records that form a continuous interval.

    • The condition_concept_id field contains Concepts that are identical to those of the CONDITION_OCCURRENCE table records that make up the Condition Era. In contrast to Drug Eras, Condition Eras are not aggregated to contain Conditions of different hierarchical layers.
    • The condition_era_start_date is the start date of the first Condition Occurrence.
    • The condition_era_end_date is the end date of the last Condition Occurrence.
  • Condition Eras are built with a Persistence Window of 30 days, meaning, if no occurrence of the same condition_concept_id happens within 30 days of any one occurrence, it will be considered the condition_era_end_date .