The Number Needed to Harm Calculator is a tool used to calculate the number of patients who have to be exposed to a certain intervention or procedure to experience one additional adverse outcome. It is a useful tool for healthcare providers to assess the risk associated with a particular treatment and how it may affect their patients. This helps healthcare providers to make informed decisions and weigh up the potential risks and benefits of each intervention.
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- IT: Incidence rate in treatment (or “exposed”) group
- IC: Incidence rate in control group
Number Needed to Harm (NNH): 50.00
Interpretation: 50.00 patients need to be exposed in order for one to experience a harmful effect, on average.
function calc() {
//get input values
var T = document.getElementById(‘T’).value*1;
var C = document.getElementById(‘C’).value*1;
//find NNH
var NNH = 1/(T-C);
//output
document.getElementById(‘NNH’).innerHTML = NNH.toFixed(2);
document.getElementById(‘NNH_out’).innerHTML = NNH.toFixed(2);
}