Definition

A standardized grading scale (1-5) developed by NCI to describe the severity of adverse events, commonly used in oncology clinical trials.

Example

Neutropenia is graded: Grade 1 (ANC <LLN-1500), Grade 2 (1000-1500), Grade 3 (500-1000), Grade 4 (<500), Grade 5 (death from neutropenia complications).

Regulatory source

NCI CTCAE v5.0

Common mistakes

Applying CTCAE grades outside the clinical trial context where they were designed, or using outdated versions.

Inspector question

How do you handle severity grading when CTCAE criteria don't exactly fit a reported event?

Related terms