Paired Interval for Proportions (McNemar)

Overview

McNemar's test and the associated confidence interval address paired binary data, such as before/after treatment comparisons on the same subjects.

Setup

For paired binary outcomes, we construct a \(2 \times 2\) table of concordant and discordant pairs. The CI focuses on the discordant pairs \(b\) and \(c\):

\[ \hat{p}_1 - \hat{p}_2 = \frac{b - c}{n} \]

McNemar's CI

The confidence interval uses the standard error based on discordant pairs.