> ## Documentation Index
> Fetch the complete documentation index at: https://help.elationhealth.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Laboratory Results Observation

## Overview

The US Core Laboratory Result Observation Profile is based upon the core FHIR Observation Resource, and, along with the [US Core DiagnosticReport Profile for Laboratory Results Reporting](/articles/fhir/uscdi-laboratory-results-diagnostic-report), meets the US Core Data for Interoperability (USCDI) v1 ‘Laboratory’ requirements. Laboratory results are grouped and summarized using the DiagnosticReport resource which reference Observation resources. Each Observation resource represents an individual laboratory test and result value, a “nested” panel (such as a microbial susceptibility panel) which references other observations, or rarely a laboratory test with component result values.

**Example Usage Scenarios:**

The following are example usage scenarios for the this profile:

* Query for lab results belonging to a Patient
* Record or update lab results belonging to a Patient

**Each Observation has next elements:**

* a category code of ‘laboratory’
* a laboratory LOINC code, if available, which tells you what is being measured

**Each Observation supports next elements:**

* a result value\*
  * if the result value is a numeric quantity, a standard UCUM unit
  * if the result value is a coded quantity, a standard SNOMED CT\*
* a specimen type (e.g., blood, serum, urine)

**Profile specific implementation guidance:**

* Additional codes that translate or map to the Observation code or category codes are allowed. For example:
  * providing both a local code and LOINC code
  * providing a more specific category codes such as ‘chemistry’, [SNOMED CT](http://hl7.org/fhir/R4/observation.html#obsgrouping) concept, or system specific codes in addition to the ‘laboratory’ category code.
* An Observation without a value, SHALL include a reason why the data is absent unless there are component observations, or references to other Observations that are grouped within it.
  * For Further guidance see the [US Core Observation Grouping](http://hl7.org/fhir/R4/observation.html#obsgrouping) section in FHIR Specification.
* See the [General US Core Guidance Section](http://hl7.org/fhir/us/core/STU6.1/general-guidance.html) page for further guidance on using SNOMED and UCUM.

This resource conforms to [USCDI V3 profile](https://www.healthit.gov/isp/uscdi-data-class/laboratory#uscdi-v3) for Observation \* refer to [StructureDefinition US Core Observation Lab](http://hl7.org/fhir/us/core/STU6.1/StructureDefinition-us-core-observation-lab.html). Observation response will be provided in JSON (refers to Capability Statement) format as per [FHIR](https://hl7.org/fhir) standard R4 version.

### Must support elements, mandatory and optional search parameters

*Observation **must support** these elements:*

* `status`
* `Slices for category`
  -`category:us-core`
* `code`
* `subject`
* `effective[x]`
* `value[x]`
* `dataAbsentReason`
* `specimen`

The syntax used to describe the interactions is described [here](/articles/fhir/us-core-guidance).

*The following search parameters and search parameter combinations SHALL be supported:*

**SHALL** support searching using the combination of the `patient` and `category` search parameters:

`GET [base]/Observation?patient={Type/}[id]&category={system|}[code]&category=http://terminology.hl7.org/CodeSystem/observation-category|laboratory`

**SHALL** support searching using the combination of the `patient` and `code` search parameters:

* including optional support for *OR* search on code (e.g.`code={system|}[code],{system|}[code],...`)

`GET [base]/Observation?patient={Type/}[id]&code={system|}[code]{,{system|}[code],...}`

**SHALL** support searching using the combination of the `patient` and `category` and `date` search parameters:

* including support for these date comparators: `gt`,`lt`,`ge`,`le`
* including optional support for *AND* search on date (e.g. `date=[date]&date=[date]]&...`)

`GET [base]/Observation?patient={Type/}[id]&category={system|}[code]&date={gt|lt|ge|le}[date]{&date={gt|lt|ge|le}[date]&...}`

*The following search parameters and search parameter combinations SHOULD be supported:*

**SHOULD** support searching using the combination of the `patient` and `category` and `status` search parameters:

* including support for OR search on status (e.g. `status={system|}[code],{system|}[code],...`)

`GET [base]/Observation?patient={Type/}[id]&category=http://terminology.hl7.org/CodeSystem/observation-category|laboratory&status={system|}[code]{,{system|}[code],...}`

**SHOULD** support searching using the combination of the `patient` and `code` and `date` search parameters:

* including optional support for *OR* search on `code` (e.g. `code={system|}[code],{system|}[code],...`)
* including support for these date comparators: `gt`,`lt`,`ge`,`le`
* including optional support for *AND* search on `date` (e.g. `date=[date]&date=[date]]&...`)

`GET [base]/Observation?patient={Type/}[id]&code={system|}[code]{,{system|}[code],...}&date={gt|lt|ge|le}[date]{&date={gt|lt|ge|le}[date]&...}`

The response to any search operation is always a list of resources in a Bundle or an Operation Outcome.

## Observation by Patient and Category

Search for Observation by combination patient and category.

**METHOD** *GET*

```
[base url]/Observation?patient={Type/}[id]&category=http://terminology.hl7.org/CodeSystem/observation-category|laboratory
```

**PARAMS**
\[base url] - [FHIR base url](/articles/fhir/service-base-urls)
\{Type/} - optional reference type
\[id] - Id for the Patient

**HEADERS**

The Authorization token SHALL be obtained during the Authentication and Authorization process. Go to [Authentication and Authorization](/articles/fhir/authentication-authorization) for further details.

| Header        | Type       | Required/Optional | Value            |
| ------------- | ---------- | ----------------- | ---------------- |
| Authorization | **string** | required          | `Bearer <token>` |

**RESPONSES**

| Code | Description                        | Comment                                                                                                                                         |
| ---- | ---------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
| 200  | OK                                 | The request was processed successfully                                                                                                          |
| 400  | Bad request                        | Invalid request parameters or FHIR operation outcome resource returned                                                                          |
| 401  | Unauthorized                       | This code indicates that the client request has not been completed because it lacks valid authentication credentials for the requested resource |
| 404  | No route matched with those values | The request was able to communicate with a given server, but the server could not find what was requested                                       |
| 500  | Internal Server Error              | The server has encountered a situation it doesn't know how to handle                                                                            |

**EXAMPLE:**

```
curl --location --request GET 'https://sandbox.fhir.elationemr.com/fhir/Observation?patient=Patient/c5137fa5-3216-b12a-cbbc-a0c6bef361g7&category=http://terminology.hl7.org/CodeSystem/observation-category|laboratory' \
--header 'Authorization: Bearer fe1cd986-1ac7-4c26-b8b3-d632a48408fd'
```

## Observation by Patient and Code

Search for Observation by combination patient and code.

**METHOD** *GET*

```
[base url]/Observation?patient={Type/}[id]&code={system|}[code]
```

**PARAMS**
\[base url] - [FHIR base url](/articles/fhir/service-base-urls)
\{Type/} - optional reference type
\[id] - Id for the Patient
\{system|} - The system for the category, e.g. [http://loinc.org](http://loinc.org)
\{code} - code for observation in the system, e.g. 44974-4

**HEADERS**

The Authorization token SHALL be obtained during the Authentication and Authorization process. Go to [Authentication and Authorization](/articles/fhir/authentication-authorization) for further details.

| Header        | Type       | Required/Optional | Value            |
| ------------- | ---------- | ----------------- | ---------------- |
| Authorization | **string** | required          | `Bearer <token>` |

**RESPONSES**

| Code | Description                        | Comment                                                                                                                                         |
| ---- | ---------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
| 200  | OK                                 | The request was processed successfully                                                                                                          |
| 400  | Bad request                        | Invalid request parameters or FHIR operation outcome resource returned                                                                          |
| 401  | Unauthorized                       | This code indicates that the client request has not been completed because it lacks valid authentication credentials for the requested resource |
| 404  | No route matched with those values | The request was able to communicate with a given server, but the server could not find what was requested                                       |
| 500  | Internal Server Error              | The server has encountered a situation it doesn't know how to handle                                                                            |

**EXAMPLE:**

```
curl --location --request GET 'https://sandbox.fhir.elationemr.com/fhir/Observation?patient=Patient/c5137fa5-3216-b12a-cbbc-a0c6bef361g7&code=http://loinc.org|2339-0,http://loinc.org|25428-4,http://loinc.org|2514-8' \
--header 'Authorization: Bearer fe1cd986-1ac7-4c26-b8b3-d632a48408fd'
```

## Observation by Patient and Category and Date

Search for Observations by combination patient and category and date.

**METHOD** *GET*

```
[base url]/Observation?patient={Type/}[id]&category=http://terminology.hl7.org/CodeSystem/observation-category|laboratory&date={gt|lt|ge|le}[date]{&date={gt|lt|ge|le}[date]&...}
```

**PARAMS**
\[base url] - [FHIR base url](/articles/fhir/service-base-urls)
\{Type/} - optional reference type
\[id] - Id for the Patient
\{system|} - The system for the category, e.g. [http://loinc.org](http://loinc.org)
\{code} - Code for observation in the system, e.g. 24323-8
\[date] - Filter's date
\{gt|lt|ge|le} - Search modifier `gr` or `lt` or `ge` or `le`. Specification [how to search by date in FHIR](http://hl7.org/fhir/R4/search.html#date)

**HEADERS**

The Authorization token SHALL be obtained during the Authentication and Authorization process. Go to [Authentication and Authorization](/articles/fhir/authentication-authorization) for further details.

| Header        | Type       | Required/Optional | Value            |
| ------------- | ---------- | ----------------- | ---------------- |
| Authorization | **string** | required          | `Bearer <token>` |

**RESPONSES**

| Code | Description                        | Comment                                                                                                                                         |
| ---- | ---------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
| 200  | OK                                 | The request was processed successfully                                                                                                          |
| 400  | Bad request                        | Invalid request parameters or FHIR operation outcome resource returned                                                                          |
| 401  | Unauthorized                       | This code indicates that the client request has not been completed because it lacks valid authentication credentials for the requested resource |
| 404  | No route matched with those values | The request was able to communicate with a given server, but the server could not find what was requested                                       |
| 500  | Internal Server Error              | The server has encountered a situation it doesn't know how to handle                                                                            |

**EXAMPLE:**

```
curl --location --request GET 'https://sandbox.fhir.elationemr.com/fhir/Observation?patient=Patient/c5137fa5-3216-b12a-cbbc-a0c6bef361g7&category=http://terminology.hl7.org/CodeSystem/observation-category|laboratory&date=ge2010-01-14T00:00:00Z' \
--header 'Authorization: Bearer fe1cd986-1ac7-4c26-b8b3-d632a48408fd'
```

## Observation by Patient and Category and Status

Search for Observations by combination patient and Category and Status.

**METHOD** *GET*

```
[base url]/Observation?patient={Type/}[id]&category=http://terminology.hl7.org/CodeSystem/observation-category|laboratory&status={system|}[code]{,{system|}[code],...}
```

**PARAMS**
\[base url] - [FHIR base url](/articles/fhir/service-base-urls)
\{Type/} - optional reference type
\[id] - Id for the Patient
\{system|} - The system for the category, e.g. [http://loinc.org](http://loinc.org)
\{code} - code for observation in the system, e.g. final

**HEADERS**

The Authorization token SHALL be obtained during the Authentication and Authorization process. Go to [Authentication and Authorization](/articles/fhir/authentication-authorization) for further details.

| Header        | Type       | Required/Optional | Value            |
| ------------- | ---------- | ----------------- | ---------------- |
| Authorization | **string** | required          | `Bearer <token>` |

**RESPONSES**

| Code | Description                        | Comment                                                                                                                                         |
| ---- | ---------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
| 200  | OK                                 | The request was processed successfully                                                                                                          |
| 400  | Bad request                        | Invalid request parameters or FHIR operation outcome resource returned                                                                          |
| 401  | Unauthorized                       | This code indicates that the client request has not been completed because it lacks valid authentication credentials for the requested resource |
| 404  | No route matched with those values | The request was able to communicate with a given server, but the server could not find what was requested                                       |
| 500  | Internal Server Error              | The server has encountered a situation it doesn't know how to handle                                                                            |

**EXAMPLE:**

```
curl --location --request GET 'https://sandbox.fhir.elationemr.com/fhir/Observation?patient=Patient/c5137fa5-3216-b12a-cbbc-a0c6bef361g7&category=http://terminology.hl7.org/CodeSystem/observation-category|laboratory&status=final' \
--header 'Authorization: Bearer fe1cd986-1ac7-4c26-b8b3-d632a48408fd'
```

## Observation by Patient and Code and Date

Search for Observations by combination patient and code and date.

**METHOD** *GET*

```
[base url]/Observation?patient={Type/}[id]&code={system|}[code]{,{system|}[code],...}&date={gt|lt|ge|le}[date]{&date={gt|lt|ge|le}[date]&...}
```

**PARAMS**
\[base url] - [FHIR base url](/articles/fhir/service-base-urls)
\{Type/} - optional reference type
\[id] - Id for the Patient
\{system|} - The system for the category, e.g. [http://loinc.org](http://loinc.org)
\{code} - code for observation in the system, e.g. 2339-0
\[date] - Filter's date
\{gt|lt|ge|le} - Search modifier `gr` or `lt` or `ge` or `le`. Specification [how to search by date in FHIR](http://hl7.org/fhir/R4/search.html#date)

**HEADERS**

The Authorization token SHALL be obtained during the Authentication and Authorization process. Go to [Authentication and Authorization](/articles/fhir/authentication-authorization) for further details.

| Header        | Type       | Required/Optional | Value            |
| ------------- | ---------- | ----------------- | ---------------- |
| Authorization | **string** | required          | `Bearer <token>` |

**RESPONSES**

| Code | Description                        | Comment                                                                                                                                         |
| ---- | ---------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
| 200  | OK                                 | The request was processed successfully                                                                                                          |
| 400  | Bad request                        | Invalid request parameters or FHIR operation outcome resource returned                                                                          |
| 401  | Unauthorized                       | This code indicates that the client request has not been completed because it lacks valid authentication credentials for the requested resource |
| 404  | No route matched with those values | The request was able to communicate with a given server, but the server could not find what was requested                                       |
| 500  | Internal Server Error              | The server has encountered a situation it doesn't know how to handle                                                                            |

**EXAMPLE:**

```
curl --location --request GET 'https://sandbox.fhir.elationemr.com/fhir/Observation?patient=Patient/c5137fa5-3216-b12a-cbbc-a0c6bef361g7&code=http://loinc.org|2339-0&date=ge2019-01-14T00:00:00Z' \
--header 'Authorization: Bearer fe1cd986-1ac7-4c26-b8b3-d632a48408fd'
```