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Numeracy in nursing

Last week there was a report in the paper bemoaning the lack of numeracy in the UK population and our indifference to our reported numerical ignorance. I can't help feeling that this might be somewhat true of nursing: when I move into a discussion of statistics such as teaching how to calculate the 'number needed to treat' (NNT) a collective moan usually goes up from the class. And if I am honest, I also share some of this trepidation. I am so much more confident with words than numbers.

I wonder why this is? The nursing profession has an honourable past in terms of our competence with mathematics. Florence Nightingale achieved most of her health care improvements because she was brilliant at statistics. She was one of the first people to adopt the use of the new pie chart to present statistics and developed a variation of this called the 'polar area diagram' which is still used today. Florence Nightingale recognised that compassion alone was not enough to campaign for change: robust data was also required. In recognition of her statistical achievements, Florence Nightingale was the first woman to be elected as member of the Royal Statistical Society and later become a member the American Statistical Society.

So with this honourable background, why do so many nurses flinch from numbers? I sometimes wonder if this is a gender issue, though if so, whether this is due to nature or nurture is open to debate. Either way, all the time we shy away from developing our numerical skills, we not only do a disservice to ourselves and our profession, we also hinder our patient care. Patients need us to be numerically competent for obvious reasons such as being able to accurately calculate drug dosages and interpret test results. However, we also need to be able to make sense of research statistics and have the skills to be able to translate study results into meaningful clinical information (which brings me back to being able to calculate a NNT).

There is light at the end of the tunnel. The nursing curriculum has an increasing emphasis on numeracy and statistics but I do think that we, as experienced clinicians, also need to face our fear of numbers to provide the positive role models needed by less experienced nurses. One postgraduate nursing student confessed to me this week that he really enjoyed statistics and was wondering whether he should choose the optional statistics module in his Masters. I hope he does - we need more nurses like him.

P.S. The NNT is the number of people you need to treat with the intervention to see one occurrence of an outcome (which is very useful to know if you are trying to decide whether it is worth investing in a new treatment). It is calculated by dividing 1 by the Absolute Risk Reduction (ARR) which is the difference in outcome rates between the two treatments.  So if there is a 0.05 (5%) difference between the two outcomes, you would need to treat 20 patients for one patient to benefit from the new treatment (1/0.05 = 20).