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

# Subjects

> Managing patient and donor records in bLIS.

## What is a Subject?

A **subject** is the person being tested — a patient, donor, or other individual. Subjects are the **top level of the data hierarchy** in bLIS. All accessions, samples, test orders, and results are organized under a subject.

Each subject has a unique **case ID** that serves as the primary identifier throughout the system.

## Data Hierarchy

Subjects are the **top level** of the data hierarchy. All other records belong to a subject:

<AccordionGroup>
  <Accordion title="Subject" icon="user">
    The patient or donor being tested. Identified by a unique **case ID**.

    A subject can have multiple accessions over time, creating a longitudinal testing history.
  </Accordion>

  <Accordion title="Accessions" icon="clipboard">
    Each accession is a batch of test orders for a specific point in time.

    One subject → Many accessions (collected over time)
  </Accordion>

  <Accordion title="Samples & Test Orders" icon="flask">
    Each accession contains:

    * **Samples** — Biological materials (blood, urine, etc.)
    * **Test Orders** — Specific tests to perform, each linked to a sample

    Samples and test orders are siblings within the accession.
  </Accordion>

  <Accordion title="Results" icon="chart-simple">
    Each test order produces one or more results.

    Results are the measured values or findings from the test.
  </Accordion>
</AccordionGroup>

## Key Fields

| Field              | Description                                                                                |
| ------------------ | ------------------------------------------------------------------------------------------ |
| **Case ID**        | The primary unique identifier for the subject (required, unique across the system)         |
| **Date of Birth**  | Used for identification and age-based reference ranges                                     |
| **Sex**            | Used for sex-specific reference ranges                                                     |
| **Type**           | Subject type (typically "donor" for transplant testing)                                    |
| **Additional IDs** | Custom identifiers like Medical Record Number, UNOS ID, or other organization-specific IDs |

<Note>
  Depending on your lab's configuration, additional identifiers may be available such as UNOS ID (for organ transplant cases) or other custom identifiers.
</Note>

## Subject History

bLIS maintains a complete history for each subject, including:

* **All accessions** — Every test batch associated with this subject
* **Result history** — All past test results, useful for tracking trends over time
* **Sample records** — All samples collected from this subject across all accessions

This history is valuable for longitudinal tracking and for comparing new results against prior values.

## Searching for Subjects

You can search for subjects using any of their identifiers:

* Name (full or partial)
* Date of birth
* Medical record number
* Case ID

<Tip>
  When creating a new accession, bLIS will search for matching subjects as you type. If a match is found, you can link to the existing record rather than creating a duplicate.
</Tip>

## Related

<CardGroup cols={2}>
  <Card title="Accessions" icon="flask" href="/concepts/accessions">
    See how subjects are linked to accessions.
  </Card>

  <Card title="Samples" icon="vial" href="/concepts/samples">
    Learn about samples collected from subjects.
  </Card>
</CardGroup>