This module compares the counts of a binary outcome under two different treatments, with statistics that are in common use in medicine. The data are entered in a 2x2 table, with treatments in rows and counts of the two different outcomes in columns.
The following example shows the results of a vaccination trial on 460 patients:
| Got influenza | Did not get influenza | |
| Vaccine | 20 | 220 |
| Placebo | 80 | 140 |
In general, the data take the form
| Outcome 1 | Outcome 2 | |
| Treatment 1 | d1 | h1 |
| Treatment 2 | d0 | h0 |
For mathematical details, see the Past manual.
Note there is currently no continuity correction.
Missing data are not allowed and will give an error message.