This February, Take Care of Yourself with Doses of Data and Heart Literacy

admin Our Thots

Word association time–what does this month mean to you?

I’m going to guess most people say ‘Valentine’s Day.’

But February is also notable as American Heart Month. Heart disease is the leading cause of death in this country (>1M lives annually!), but it is also one of the most preventable illnesses with proper use of exercise, diet, and medications, as well as a little heart literacy. Given this, individuals are inundated with a wide variety of suggestions on how they can lower their risk or reduce the severity of their illness. Should you take a baby aspirin daily? Does a low cholesterol diet make sense? What about taking fish oil? Should everyone over 65 take a statin by default?

Contributing to Heart Literacy

As analysts, our contribution to increasing awareness about heart disease (and heart literacy) lies in not just the ability to mine healthcare data to look at the results of different treatments. We also can provide valuable statistics regarding the efficacy of treatments. That is, methods exist to quantify the benefit of treatment in light of one’s individual risk of an illness. One of my favorites—often used in the clinical trial community—is the concept of the ‘Number Needed to Treat’ or NNT. This figure tells us how many people need to get treatment for one person to receive a benefit. For example, an NNT of 10 means that for every ten people given a treatment, one will improve.

Number Needed to Treat (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.


So what is a common NNT for a given therapy?  One? Five? Ten? What if I told you that NNT commonly ranks in the hundreds or thousands? How would that impact your decision to engage in that treatment? For most of us, that decision would depend on the risk, annoyance, and cost of the treatment.

So back to heart literacy and American Heart Month, what is the NNT for many of the conventional heart disease prevention therapies?  I fell upon this fantastic site that curates NNT information based upon a thorough review of available research.

So let’s look at some examples:

Number Needed to Treat Values for Common Heart Disease Treatments

Data courtesy of

Do any of these surprise you?

So for the Mediterranean diet, if 61 people followed it religiously for five years, one serious heart-related event would have been prevented. The thing is, we can’t know who that person will be. To put it another way, the is a 1/61 or 16.4% chance that the diet will prevent the event.

NNT Isn’t Perfect, But When it Comes to Heart Literacy, it is Valuable

Now the NNT is by no means perfect and as with any metric, there are limitations. The NNT is only usable as a reference to compare therapies if those therapies were tested in similar populations, under the same conditions (such as stage of disease), on the same outcomes (such as death), and over similar time frames.

However, NNT is an important concept that we need to use more often when building heart literacy and thinking about the impact of a change to our healthcare. Especially with precision medicine advancements coming on strong as a means to tailor treatments to an individual’s unique physiology and lifestyle.

If you are interested in improving your literacy with risk scores, join us for our workshop, Understanding and Communicating Risk: Critical Competencies for the Healthcare Workforce, at the iHealth 2017 Clinical Informatics Conference – May 2 – 4, Philadelphia. It’s going to be a great event!