Suppose a protocol states:
“Weight and height shall be measured at enrollment and Day 28. Nutritional status will be assessed using weight-for-height Z scores.”
Data manager actions:
Step 1:
Identify required variables.
- weight_kg
- height_cm
Step 2:
Determine collection visits.
- Enrollment
- Day 28
Step 3:
Design CRF fields.
Weight (kg):
Numeric, one decimal place.
Height (cm):
Numeric, one decimal place.
Step 4:
Add validation.
Weight:
1–200 kg
Height:
20–250 cm
Step 5:
Plan derived variable.
WHZ score calculated during analysis.
This example illustrates how protocol requirements are transformed into practical data collection tools.