Be Aware: Health Risk Statistics could damage your health

If you are about to make a major health related decision on the basis of the statistics provided by your healthcare professional you really need to make sure you are aware of three different statistical presentations of risk reduction.

This is because both the healthcare professionals and patients/consumers are most likely to change their choices when the same risks and risk reductions are presented using alternative statistical formats, namely:

  • Relative Risk Reduction (RRR)
  • Absolute Risk Reduction (ARR)
  • Number Needed to Treat (NNT)

To illustrate, imagine your doctor tells you that having a certain operation or taking a certain pill will:

A. Cut your risk of getting a serious disease in half – a 50% reduction. Would you have the operation/take the pill?

Now suppose you were instead told that;

B. The risk is 2% for people who do not have the operation/take the pill but your risk will be reduced to 1%. What would your decision be now?

And what if you were instead told that;

C. Only one of every 100 patients who have the operation/take the pill will actually benefit from it. Would you still make the same decision?

In the examples above the doctor is presenting the same information in different ways – in example A the format used is RRR and examples B and C use the ARR  and  NNT format respectively.

At ClickTell we have been aware of such practices and have had anecdotal evidence that this does affect healthcare decisions.

The findings of a March 2011 Review of Studies including scientific literature going as far back as 1887 and published in The Cochrane Library show that both doctors and patients are largely unaware of these different ways of presenting the same information. The findings also demonstrate that the format in which the data is presented has a profound influence on healthcare decisions.

Contact ClickTell to find out how we can help you or your organisation to make more informed evidence-based decisions.


James Usher said...

Wow, My mom is just going through a tough time having to make a decision along the lines of your post. This is REALLY useful.

Anonymous said...

O.K. as a healthcare professional I had to read it twice to understand.

This is a simple but fundamental issue which should be widely discussed.

Inspiring and worrying.

Keep up the good work and thanks for sharing.

Carol said...

Interesting research. There really are some things in life that could be life-changing.

Joseph C said...

How smart is that. You guys are Toooooo brainy for me.
Seriously thanks for sharing this. REALLY educational.