Why proper understanding of confidence intervals and statistical significance is important

Karla Hemming and Monica Taljaard
Med J Aust 2021; 215 (4): . || doi: 10.5694/mja2.51186
Published online: 16 August 2021

In reply: In our medical education article,1 we aimed to provide practical recommendations for more informative interpretation of findings from randomised controlled trials based on considering the range of effects supported by the data. We sought to discourage the types of misinterpretations that are far too common, as illustrated by the two examples we provided. We recommended that, even when the upper or lower limit of the confidence interval (CI) overlaps with the null, researchers avoid conclusions of “non‐statistically significant” in favour of more directive conclusions that consider the width of the CI and whether it overlaps with clinically important differences, suggesting that values towards the limits of the CIs have less support from the data.

  • Karla Hemming1
  • Monica Taljaard2

  • 1 Institute of Applied Health Research, University of Birmingham, Birmingham, UK
  • 2 Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada


Competing interests:

No relevant disclosures.


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