# CD4 Testing and Staging Workflow

## Purpose
This page outlines the clinical workflow for CD4 testing and AHD staging within the ART POC module.

## Step-by-Step

1. **CD4 Test Entry**
   - Enter CD4 result or place lab order.
   - Capture test location and date.

2. **Auto-Staging**
   - System computes WHO staging based on symptoms and test results.
   - CD4 < 200 triggers AHD warning.

3. **Trigger Criteria for AHD Screening**
   - CD4 < 200
   - WHO stage 3 or 4
   - Critical illness flags from vitals

4. **System Prompt**
   - System presents a pop-up:
     > "Client meets AHD screening criteria. Proceed to OI screening?"

## Data Elements
| Field | Type | Required | Notes |
|-------|------|----------|-------|
| cd4_result | Integer | Yes | Required for AHD trigger |
| test_date | Date | Yes | |
| test_location | Text | Yes | Lab name |