Glossary Term

NNH

Number Needed to Harm (NNH) is a clinical measure indicating how many patients must be exposed to a treatment for one additional patient to experience a specific adverse outcome or harm.

Illustration representing NNH
Listen to definition
Related terms
NNT RR SAE
Further reading
Wikipedia: Number Needed to Harm Browse the HEOR resource database

Spotted an error or have a suggestion? Get in touch

Media Kit · Q2 2026

Where should we send it?

Quick details so we can email the kit and follow up if it's a fit. We use this only to talk to you about sponsorship — never sold or shared.

Your details stay with Mirko von Hein. No newsletter sign-ups, no third-party sharing.