Number Needed to Harm
How many people have to be treated to cause a future bad outcome?
Number Needed to Harm (NNH) tells clinicians how many people that have to be treated to cause a bad outcome. The formula for number needed to harm is (1/ARI). As the absolute risk increase goes up, the number needed to harm will decrease, meaning that the treatment will likely cause negative outcomes.
Clinicians ultimately want number needed to harm to be HIGH, meaning that many people need to be treated before a bad outcome occurs.
Clinicians ultimately want number needed to harm to be HIGH, meaning that many people need to be treated before a bad outcome occurs.
Number Needed to Harm (NNH)
Click on the Download Database button for a database structured for epidemiological data. Click on the Download Calculator button to download a free epidemiological calculator.
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