The NNT
There is a way of understanding how much modern medicine has to offer individual patients. It is a simple statistical concept called the “Number-Needed-to-Treat”, or for short the ‘NNT’. 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. The concept is statistical, but intuitive, for we know that not everyone is helped by a medicine or intervention — some benefit, some are harmed, and some are unaffected. The NNT tells us how many of each.
For every therapy we review, we provide a color-coded summary for you to use (borrowed from the traditional stoplight). As we state in our philosophy, we care about benefits and harms that matter to patients, not researchers. Patients care about death and illness, not a laboratory value or CT scan finding. We use this focus on "patient-important outcomes" to guide our recommendations.