FHIR CodeSystem/$find-matches for property search - OMOPHub.com API

Overview

Returns concepts matching a set of property criteria. This is a reverse lookup — “find me concepts with these characteristics” rather than “look up this specific code.” Maps to OMOPHub’s search capabilities with domain, vocabulary, and concept class filters.

Request

curl -X POST "https://fhir.omophub.com/fhir/r4/CodeSystem/\$find-matches" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/fhir+json" \
  -d '{
    "resourceType": "Parameters",
    "parameter": [
      { "name": "system", "valueUri": "http://snomed.info/sct" },
      {
        "name": "property",
        "part": [
          { "name": "code", "valueCode": "domain-id" },
          { "name": "value", "valueCode": "Condition" }
        ]
      }
    ]
  }'

$find-matches requires structured property parameters with code and value parts. Use POST with a FHIR Parameters body - GET query strings cannot express this structure.

Parameters

Parameter	Type	Required	Description
`system`	uri	No	Code system to search within
`property`	composite	No (repeatable)	Property criteria (code + value pair). If omitted, returns a broad search.

Supported Property Codes

Property Code	Description	Example Value
`domain-id`	OMOP domain	`Condition`, `Drug`, `Measurement`, `Procedure`
`vocabulary-id`	OMOP vocabulary	`SNOMED`, `ICD10CM`, `LOINC`, `RxNorm`
`concept-class-id`	Concept class	`Clinical Finding`, `Ingredient`, `Lab Test`
`standard-concept`	Standard status	`S` (Standard), `C` (Classification)
`concept-name`	Text search	`diabetes`, `myocardial`

Response

{
  "resourceType": "Parameters",
  "parameter": [
    {
      "name": "match",
      "part": [
        {
          "name": "concept",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "44054006",
            "display": "Type 2 diabetes mellitus"
          }
        }
      ]
    },
    {
      "name": "match",
      "part": [
        {
          "name": "concept",
          "valueCoding": {
            "system": "http://snomed.info/sct",
            "code": "73211009",
            "display": "Diabetes mellitus"
          }
        }
      ]
    }
  ]
}