MedicationRequest → drug_exposure (FHIR-flat, stage 1)

{
  "resourceType": "ViewDefinition",
  "id": "omop-medicationrequest-drug-exposure",
  "url": "https://fhir2omop.health-samurai.io/ViewDefinition/omop-medicationrequest-drug-exposure",
  "version": "0.2.0",
  "name": "OmopMedicationRequestDrugExposureView",
  "title": "MedicationRequest → drug_exposure (FHIR-flat, stage 1)",
  "status": "draft",
  "experimental": true,
  "description": "Prescription/order stage of the medication lifecycle. One FHIR MedicationRequest maps to one OMOP drug_exposure row. MedicationRequest is the richest of the four FHIR medication-event resources for OMOP purposes because it carries dispense, refill, and supply-duration metadata that the other three lack. Type concept 38000177 (Prescription written).\n\nStage 1 of FHIR→OMOP: produce a flat row keeping source codes per vocabulary. Stage 2 joins vocab.concept to resolve concept_ids.",
  "extension": [
    {
      "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-target-table",
      "valueString": "drug_exposure"
    },
    {
      "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-edge",
      "valueString": "MedicationRequest__drug_exposure"
    }
  ],
  "resource": "MedicationRequest",
  "select": [
    {
      "column": [
        {
          "name": "id",
          "path": "MedicationRequest.id",
          "type": "id",
          "description": "FHIR MedicationRequest.id; surrogate OMOP key derived (hash/sequence) downstream.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "drug_exposure_id"
                },
                {
                  "url": "transform",
                  "valueString": "surrogate key from hash/sequence/lookup of FHIR id"
                }
              ]
            }
          ]
        },
        {
          "name": "drug_rxnorm",
          "path": "MedicationRequest.medicationCodeableConcept.coding.where(system='http://www.nlm.nih.gov/research/umls/rxnorm').first().code",
          "type": "code",
          "description": "Medication code — RxNorm",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "drug_concept_id"
                },
                {
                  "url": "transform",
                  "valueString": "lookup vocab.concept WHERE vocabulary_id='RxNorm' AND concept_code = (this column); standard_concept='S' preferred"
                }
              ]
            }
          ]
        },
        {
          "name": "drug_ndc",
          "path": "MedicationRequest.medicationCodeableConcept.coding.where(system='http://hl7.org/fhir/sid/ndc').first().code",
          "type": "code",
          "description": "Medication code — NDC",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "drug_concept_id"
                },
                {
                  "url": "transform",
                  "valueString": "lookup vocab.concept WHERE vocabulary_id='NDC' AND concept_code = (this column); standard_concept='S' preferred"
                }
              ]
            }
          ]
        },
        {
          "name": "drug_atc",
          "path": "MedicationRequest.medicationCodeableConcept.coding.where(system='http://www.whocc.no/atc').first().code",
          "type": "code",
          "description": "Medication code — ATC",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "drug_concept_id"
                },
                {
                  "url": "transform",
                  "valueString": "lookup vocab.concept WHERE vocabulary_id='ATC' AND concept_code = (this column); standard_concept='S' preferred"
                }
              ]
            }
          ]
        },
        {
          "name": "drug_snomed",
          "path": "MedicationRequest.medicationCodeableConcept.coding.where(system='http://snomed.info/sct').first().code",
          "type": "code",
          "description": "Medication code — SNOMED",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "drug_concept_id"
                },
                {
                  "url": "transform",
                  "valueString": "lookup vocab.concept WHERE vocabulary_id='SNOMED' AND concept_code = (this column); standard_concept='S' preferred"
                }
              ]
            }
          ]
        },
        {
          "name": "drug_text",
          "path": "MedicationRequest.medicationCodeableConcept.text",
          "type": "string",
          "description": "Free text label from MedicationRequest.medicationCodeableConcept",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "drug_source_value"
                },
                {
                  "url": "transform",
                  "valueString": "copy text verbatim into OMOP source_value column"
                }
              ]
            }
          ]
        },
        {
          "name": "subject_id",
          "path": "MedicationRequest.subject",
          "type": "Reference(Patient)",
          "description": "Resolve Patient reference to integer person_id. If unresolvable, omoponfhir throws FHIRException; FhirToCdm skips the record; this project defaults to 0.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "person_id"
                },
                {
                  "url": "transform",
                  "valueString": "resolve PERSON reference; downstream maps to person_id"
                }
              ]
            }
          ]
        },
        {
          "name": "drug_exposure_start_date",
          "path": "MedicationRequest.authoredOn",
          "type": "dateTime",
          "description": "The date the prescription was authored. NACHC falls back to encounter start date if null. FhirToCdm derives from VisitOccurrence instead.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "drug_exposure_start_date"
                }
              ]
            }
          ]
        },
        {
          "name": "drug_exposure_start_datetime",
          "path": "MedicationRequest.authoredOn",
          "type": "dateTime",
          "description": "Full ISO datetime from authoredOn.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "drug_exposure_start_datetime"
                }
              ]
            }
          ]
        },
        {
          "name": "drug_exposure_end_date",
          "path": "MedicationRequest.dispenseRequest.validityPeriod.end",
          "type": "dateTime",
          "description": "If absent, fallback to start date. This project also derives end from dispenseRequest.expectedSupplyDuration only when validityPeriod.end is absent.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "drug_exposure_end_date"
                }
              ]
            }
          ]
        },
        {
          "name": "drug_exposure_end_datetime",
          "path": "MedicationRequest.dispenseRequest.validityPeriod.end",
          "type": "dateTime",
          "description": "Full ISO datetime. Null if no end available.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "drug_exposure_end_datetime"
                }
              ]
            }
          ]
        },
        {
          "name": "stop_reason",
          "path": "MedicationRequest.statusReason",
          "type": "CodeableConcept",
          "description": "Reason for discontinuation. omoponfhir truncates to 20 chars. Only populated when status = stopped. Most implementations leave null.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "stop_reason"
                }
              ]
            }
          ]
        },
        {
          "name": "refills",
          "path": "MedicationRequest.dispenseRequest.numberOfRepeatsAllowed",
          "type": "integer",
          "description": "Number of refills. omoponfhir reads from dispenseRequest as fallback when dosageInstruction is empty. Only applicable to MedicationRequest.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "refills"
                }
              ]
            }
          ]
        },
        {
          "name": "quantity",
          "path": "MedicationRequest.dosageInstruction[0].doseAndRate[0].doseQuantity.value",
          "type": "decimal",
          "description": "Dose amount per administration. omoponfhir also reads dispenseRequest.quantity.value as fallback. ETL-German computes mean of Range when doseRange is used.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "quantity"
                }
              ]
            }
          ]
        },
        {
          "name": "days_supply",
          "path": "MedicationRequest.dispenseRequest.expectedSupplyDuration",
          "type": "Duration",
          "description": "Days of medication supply. Calculated from expectedSupplyDuration.value with UCUM unit conversion. This project converts h/d/wk/mo/a units. No reference implementation populates this.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "days_supply"
                },
                {
                  "url": "transform",
                  "valueString": "convertUcumDuration(value, unit) -- h/d/wk/mo/a to days"
                }
              ]
            }
          ]
        },
        {
          "name": "sig",
          "path": "MedicationRequest.dosageInstruction[0].text",
          "type": "string",
          "description": "Free-text dosage instructions. FhirToCdm reads dosageInstruction[0].text. fhir-to-omop-demo uses .note.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "sig"
                }
              ]
            }
          ]
        },
        {
          "name": "route",
          "path": "MedicationRequest.dosageInstruction[0].route",
          "type": "CodeableConcept",
          "description": "Administration route. Requires vocabulary lookup against SNOMED route concepts. This project currently sets null and captures route_source_value only.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "route_concept_id"
                },
                {
                  "url": "transform",
                  "valueString": "resolve CONCEPT reference; downstream maps to route_concept_id"
                }
              ]
            }
          ]
        },
        {
          "name": "route_text",
          "path": "MedicationRequest.dosageInstruction[0].route.text",
          "type": "string",
          "description": "Raw route code or display text. omoponfhir prefers route.text, falls back to coding[0].display.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "route_source_value"
                }
              ]
            }
          ]
        },
        {
          "name": "performer_id",
          "path": "MedicationRequest.requester",
          "type": "Reference(Practitioner)",
          "description": "Prescriber. omoponfhir uses recorder instead. This project uses requester.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "provider_id"
                },
                {
                  "url": "transform",
                  "valueString": "resolve PROVIDER reference; downstream maps to provider_id"
                }
              ]
            }
          ]
        },
        {
          "name": "encounter_id",
          "path": "MedicationRequest.encounter",
          "type": "Reference(Encounter)",
          "description": "Resolve Encounter reference. omoponfhir validates that the referenced VisitOccurrence exists in the database.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "visit_occurrence_id"
                },
                {
                  "url": "transform",
                  "valueString": "resolve VISIT_OCCURRENCE reference; downstream maps to visit_occurrence_id"
                }
              ]
            }
          ]
        },
        {
          "name": "dose_unit_text",
          "path": "MedicationRequest.dosageInstruction[0].doseAndRate[0].doseQuantity.unit",
          "type": "string",
          "description": "Raw dose unit string. omoponfhir prefers .code, falls back to .unit.",
          "extension": [
            {
              "url": "https://fhir2omop.health-samurai.io/StructureDefinition/omop-column-target",
              "extension": [
                {
                  "url": "column",
                  "valueString": "dose_unit_source_value"
                }
              ]
            }
          ]
        }
      ]
    }
  ],
  "targetTable": "drug_exposure",
  "edgeKey": "MedicationRequest__drug_exposure"
}