McNemar test

The McNemar test is used to test the difference between paired proportions, for example in studies in which patients serve as their own control, or in studies with "before and after" design.

How to enter the data in the data table

Required input

Select two discrete variables with related classification data. Classification data may either be numeric or alphanumeric (string) values, but both variables cannot contain more than 2 different classification values.


The results section for the McNemar test displays:

Frequency table

The 2x2 classification table.


The program gives the difference between the proportions (expressed as a percentage) with 95% confidence interval. When the (two-sided) P-value is less than the conventional 0.05, the conclusion is that there is a significant difference between the two proportions.


The two-sided P-value is based on the cumulative binomial distribution.

The 95% confidence interval is calculated according to Sheskin, 2011.


  • Altman DG (1991) Practical statistics for medical research. London: Chapman and Hall.
  • Sheskin DJ (2011) Handbook of parametric and nonparametric statistical procedures. 5th ed. Boca Raton: Chapman & Hall /CRC.

See also


Go to McNemar test.