Background & Scope

Traditionally, a location refers to the physical place where healthcare services are provided, practitioners are employed, and organizations are based. This information is captured by the position element. For the National Directory, there is a need to address insurance plan coverage areas and insurance provider network coverage areas. This information is defined by the location-boundary-geojson extension element.

Search Parameters

Search Parameter defined by the NDH IG

Search Parameter defined by FHIR Search Parameter Registry and used by the NDH IG

Since there is no direct individual url for each Search Parameter defined by FHIR Serach Parameter Registry, we have provided the following links for you to access more information about them.

• Search Parameter Registry
• Location Search Parameter from Registry

_include Search Parameter

_revinclude Search Parameter

Special Search Parameters

The search parameters outlined above are straightforward for basic scenarios but have limitations in handling complex combination queries. To enhance these capabilities, employing the special search parameters _filter is recommended.

Search for locations with managing organization

The FHIR path for the managing organization is Location.managingOrganization, but the search parameter is organization. For example, to search for all locations assoicated with an managingOrganization has ID Hospital should write as:

GET [base]/Location?organization=Organization/Hospital

You can also search for locations associated with the managing organizations by name or other criteria. For example, to search for all locations associated with an organization with the name of Hartford General Hospital:

GET [base]/Location?organization:Organization.name=Hartford General Hospital

You can add additional search criteria to further narrow down your search results. For example, to search for all locations associated with the Hartford General Hospital organization that have a status of active:

GET [base]/Location?organization:Organization.name=Hartford General Hospital&status=active

Including other resources in search result

You can search for all Locations and their associated related resources (in this case, organization) which are managering some of locations. The _include parameter to indicate that the managingOrganization resources be included in the result.

GET [base]//Location?_include=Location:organization

Search location-boundary-geojson

GeoJSON encodes spatial data structures, including points, lines, polygons, and multi-part collections of these types. It is a common format for representing simple geographic features along with their non-spatial attributes. For example, a polygon area for Washington, D.C. is represented as:

{
  "type"": ""Feature",
  "geometry": {
    "type": "Polygon",
    "coordinates": [
      [
        [-77.119759, 38.934343],
        [-77.041697, 38.99511],
        [-76.910535, 38.892912],
        [-77.038088, 38.791015],
        [-77.119759, 38.934343]
      ]
    ]
  },
  "properties": {
    "name"": "Washington, D.C."
  }
}

How to populate the location-boundary-geojson data in Location resource

The data type of the location-boundary-geojson is Attachment, with the contentType set to application/geo+json and the data formatted as base64Binary. To represent a polygon area for Washington, D.C., you can use a JSON to Base64 converter to transform the JSON data into base64Binary format, which will look like this:

{
  "resourceType" : "Location",
  "id" : "wash-dc-metro",
  "meta" : {
    "profile" : ["http://hl7.org/fhir/uv/vhdir/StructureDefinition/vhdir-location"]
  },
  "text" : {
    "status" : "extensions",
    "div" : "<div xmlns=\"http://www.w3.org/1999/xhtml\"><p><b>Generated Narrative: Location</b><a name=\"wash-dc-metro\"> </a></p><div style=\"display: inline-block; background-color: #d9e0e7; padding: 6px; margin: 4px; border: 1px solid #8da1b4; border-radius: 5px; line-height: 60%\"><p style=\"margin-bottom: 0px\">Resource Location &quot;wash-dc-metro&quot; </p><p style=\"margin-bottom: 0px\">Profile: <code>http://hl7.org/fhir/uv/vhdir/StructureDefinition/vhdir-location</code></p></div><p><b>Location Boundary (GeoJSON)</b>: </p><p><b>status</b>: active</p><p><b>name</b>: <span title=\"  this record is active  \">Washington, DC metro area</span></p><p><b>form</b>: Area <span style=\"background: LightGoldenRodYellow; margin: 4px; border: 1px solid khaki\"> (<a href=\"http://terminology.hl7.org/5.3.0/CodeSystem-location-physical-type.html\">Location type</a>#area)</span></p></div>"
  },
  "extension" : [{
    "url" : "http://hl7.org/fhir/StructureDefinition/location-boundary-geojson",
    "valueAttachment" : {
      "contentType" : "application/geo+json",
      "data" : "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",
      "url" : "https://github.com/OpenDataDE/State-zip-code-GeoJSON/raw/master/dc_district_of_columbia_zip_codes_geo.min.json",
      "size" : "389"
    }
  }],
  "status" : "active",
  "name" : "Washington, DC metro area",
  "form" : {
    "coding" : [{
      "system" : "http://terminology.hl7.org/CodeSystem/location-physical-type",
      "code" : "area",
      "display" : "Area"
    }]
  }
}

How to search location-boundary-geojson

The special contains search parameter tests whether the provided geocoded point(s) (expressed as [latitude]|[longitude] using the WGS84 datum) are within the defined boundary. Support for multiple points can also be provided using the , syntax, which is interpreted as the location returned in the search containing at least one of the provided coordinates. For example, for the Washington, D.C. polygon area:

GET [base]/Location?contains=-77.119759|38.934343,-77.041697|38.99511,-76.910535|38.892912,-77.038088|38.791015,-77.119759|38.934343