This calculator helps healthcare professionals determine the Number Needed to Harm (NNH), which indicates how many patients need to be exposed to a risk factor for one patient to experience harm. It assists in evaluating the side effects of medical treatments.
All calculations are rigorously based on statistical formulas for epidemiological studies. For further reading, refer to clinical guidelines and scientific literature.
NNH = 1 / (Incidence in Treated Group - Incidence in Control Group)
Consider a drug trial where 5% of the treated group and 2% of the control group experience a certain side effect. The NNH would be calculated as follows:
NNH = 1 / (0.05 - 0.02) = 33.33
Number Needed to Harm (NNH) is a measure used in epidemiology to describe the effectiveness of a treatment in terms of adverse effects.
NNH is calculated using the formula: NNH = 1 / (Incidence in Treated Group - Incidence in Control Group).
NNH helps in understanding the risk of adverse effects from a treatment, aiding in informed decision-making.
No, NNH should always be a positive number. If the calculation results in a negative number, it indicates that the treatment is beneficial rather than harmful.
While NNH measures harm, Number Needed to Treat (NNT) measures the effectiveness of a treatment in achieving a beneficial outcome.