Why Reviewers Now Demand Use Error Analysis in Your CER

Written by HATEM RABEH, MD, MSc Ing

Your Clinical Evaluation Expert And Partner

in
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This scenario is becoming routine. What was once considered part of usability engineering is now appearing as a clinical evaluation requirement. Reviewers want to see use error analysis directly in your CER. Not as an attachment. Not referenced vaguely. But analyzed, discussed, and integrated into your benefit-risk assessment.

The shift is not arbitrary. It comes from a clearer interpretation of MDR Article 61 and how clinical data must include real-world use conditions. If use errors contribute to harm, they belong in your clinical evaluation. If they do not, you need to show why.

What Use Error Analysis Actually Means

Use error analysis is not a list of complaints. It is a structured review of how users interact with your device under real conditions and what happens when that interaction goes wrong.

IEC 62366 defines use error as an act or omission that results in a different response than intended by the manufacturer. The user presses the wrong button. They misinterpret a display. They skip a step. The device delivers an incorrect dose. Or no dose at all.

In usability engineering, you identify these errors during formative and summative testing. You assess risk. You implement mitigations. You document everything in your usability file.

But clinical evaluation asks a different question: what does the clinical data say about these errors in practice?

Why This Is Becoming a Standard Request

For years, clinical evaluation and usability engineering ran on parallel tracks. The CER focused on efficacy and safety from clinical studies. The usability file focused on human factors testing and design mitigations. Reviewers looked at each file separately.

That separation no longer holds. Notified Bodies now expect integration.

The reason is simple. Real-world harm often comes from use errors, not device malfunctions. A pump delivers the correct dose when tested in the lab but is misused at the bedside. A diagnostic device produces accurate results in trained hands but fails when used by less experienced operators. The failure is not mechanical. It is contextual.

If your CER does not address this, it is incomplete. It presents a picture of performance under ideal conditions, not the conditions your users actually face.

Reviewers see this gap. They ask: where is the analysis of how users interact with the device? What errors have been observed post-market? How do those errors affect clinical outcomes? What mitigations have been validated in the field?

If your answer is