# Retrieve a patient's diagnostic results

You can use this API action to access a provider's findings or interpretations of a diagnostic procedure, as documented by a specific organization. 

## Use cases

This API action may be a good fit for your organization if you perform any of these use cases:

- Track the completion of a diagnostic procedure for a patient.
- Review documents with a provider’s interpretation of a diagnostic procedure (e.g., interpretation of an MRI).
- Provide access to one or more result documents on a mobile app for users.
- Review interpretation results of a diagnostic procedure for billing or coding purposes.
- Review laboratory data or imaging results.
- Recommend a course of treatment based on test results.

> **Prerequisite: Having a patient identifier**
>
> To use this API action, you must know the patient identifier. If you don’t have one, [search for a patient with demographics](/fhir-api-actions/patients/search-for-a-patient-by-demographics) to locate an appropriate identifier first.

The returned data fields may be free text or discrete data/images.

## Supported systems

You can use this API action with the Redox FHIR API.

> **Talk to a Redoxer**
>
> It’s also possible to use the Redox Data Model API for this API action. [Talk to a Redoxer](https://redoxengine.com/forms/contact-us/) to learn about your options.

Your connection's system can return results with their own FHIR or query-based API. 

> **Using data on demand**
>
> Your connection's system may not support a query-based data exchange, but they may still be willing to provide results with a push-based method.
>
> However, we understand that you may not want to store all that data. Maybe you don't need _all_ the possible results and just want to query for what you want when you need it. If so, you can use this API action via our <u>data on demand</u> service, which stores the connection's data so that you can query from Redox "on demand." [Learn about data on demand](/basics/data-exchange-with-redox/data-on-demand).

## Things you need to know

<details>
<summary>Lab result codes</summary>

Lab values can be numeric or text strings. Alternatively, they can be represented in a report style (e.g., a CT scan with the provider's interpretation) or with Logical Observation Identifiers, Names, and Codes (LOINC) or Current Procedural Terminology (CPT) codes. Usually, test results are returned in a mix of any of these formats.  

Sometimes an EHR system uses non-standard codes as well, so you may need to account for EHR-specific codes for test types or results.

</details>

<details>
<summary>Observation or diagnostic report</summary>

A patient's diagnostic results may include an observation or a collection of observations that are grouped into a diagnostic report. There are separate action steps for you to query for these, depending on whether you're searching for an observation or a diagnostic report. You can use just one action step or both. 

</details>

> **What's next? **
>
> Does this API action seem like a good fit for your unique workflow? Let your Technical Account Manager know! To start development, download the resource schema noted in the related action step. Then decide which data elements you need.
>
> If you’re new to Redox, [use the Quickstart guide](/quickstart-for-redox) to dive in. If you’re not engaged with our sales team yet, [talk to a Redoxer](https://redoxengine.com/forms/contact-us/) to get started.