A brief note on overlapping confidence intervals

J Vasc Surg. 2002 Jul;36(1):194-5. doi: 10.1067/mva.2002.125015.


Clinical researchers frequently assess the statistical significance of the difference between two means by examining whether the two 95% confidence intervals overlap. The purpose of this brief communication is to illustrate that the 95% confidence intervals for two means can overlap and yet the two means can be statistically significantly different from one another at the alpha = 0.05 level.

MeSH terms

  • Confidence Intervals*
  • Data Interpretation, Statistical
  • Humans