Statistical Procedure

This procedure can be used when the:

Outcome (Dependent) variable is a Binary measure
Exposure (Independent) variable is Paired (related) sample - 2 time points

Present this graphically using a Clustered or Stacked Bar Chart

In SPSS select: Graphs > Chart Builder - Gallery – Bar | Clustered Bar or Stacked Bar

Analyse this in SPSS using:

Analyze >Descriptive Statistics > Crosstabs
Use the Statistics button and select McNemar, Exact button and select Exact

The Exact Sig. (2-sided) is the p-value.

Report this quoting the:

Difference in proportions, 95%CI and p-value
Use Confidence Interval Analysis (CIA)Proportions and their differences | Paired Samples to calculate these values

Comments

If you have total counts for a 2 * 2 table. SPSS can analyse this using Weight Cases. See Field's book p693.

References

Chapter 18, p694 in Discovering Statistics using SPSS 3rd Edition, A. Field, Sage Publications (2009) (ISBN: 9781847879073)

Please Report any issues to Brian Yuen