How do you explain NNT?

The Number Needed to Treat (NNT) is the number of patients you need to treat to prevent one additional bad outcome (death, stroke, etc.). For example, if a drug has an NNT of 5, it means you have to treat 5 people with the drug to prevent one additional bad outcome.

What is an acceptable NNT for a drug?

As a general rule of thumb, an NNT of 5 or under for treating a symptomatic condition is usually considered to be acceptable and in some cases even NNTs below 10.

Is a high or low NNT better?

The ideal NNT is 1, where everyone improves with treatment and no one improves with control. A higher NNT indicates that treatment is less effective. NNT is similar to number needed to harm (NNH), where NNT usually refers to a therapeutic intervention and NNH to a detrimental effect or risk factor.

How do you explain relative risk reduction?

The relative risk reduction is the difference in event rates between two groups, expressed as a proportion of the event rate in the untreated group. For example, if 20\% of patients die with treatment A, and 15\% die with treatment B, the relative risk reduction is 25\%.

What is meant by the terms numbers needed to treat and number needed to harm?

The “numbers needed to harm” (NNH) is the number needed to treat with a certain drug before a patient experience a significant side effect. The NNH of several drugs for pain management is not yet known.

Why is NNT an important concept for prescribers?

The Basic Idea There is a way of understanding how much modern medicine has to offer individual patients. The NNT offers a measurement of the impact of a medicine or therapy by estimating the number of patients that need to be treated in order to have an impact on one person.

How do you work out NNT?

The NNT is simply the inverse of the ARR; it can be calculated by taking 100 and dividing it by the ARR (1).

What does low NNT mean?

Treatments. NNT can be used to help us choose between two treatment options. If, for example, the NNT for drug A is lower than that for drug B, it suggests that drug A may be more effective and – all other things being equal – choosing A rather than B would make sense.

How do you calculate number needed to treat relative risk?

A certain risk reduction may appear impressive but how many patients would you have to treat before seeing a benefit? This concept is called “number need to treat” and is one of the most intuitive statistics for clinical practice. The RR = (8/1000) / (10/1000) = 0.8 making the RRR = (1-0.8/1)=0.2 or 20\%.

How do you do number needed to treat?

NNTs are always rounded up to the nearest whole number and accompanied as standard by the 95\% confidence interval. Example: if a drug reduces the risk of a bad outcome from 50\% to 40\%, the ARR = 0.5 – 0.4 = 0.1. Therefore, the NNT = 1/ARR = 10. The ideal NNT would be 1 – ie all patients treated will benefit.

What does intention to treat mean in research?

Intention-to-treat analysis is a method for analyzing results in a prospective randomized study where all participants who are randomized are included in the statistical analysis and analyzed according to the group they were originally assigned, regardless of what treatment (if any) they received.

Can you calculate NNT if not statistically significant?

When the ARR is non-significant, by definition its confidence interval includes or touches zero. The confidence interval for the corresponding NNT will straddle plus and minus infinity.