Often, the outcome of interest is an "event", with the data taking a binary form; the event either did or did not occur. This data is easily summarised in a two-by-two table, as follows:
| Event | No event |
Total |
|
| Treated (or exposed) |
a | b | a+b |
| Control (or unexposed) |
c | d | c+d |
| Total | a+c |
b+d |
a+b+c+d |
Exercise
In a trial of MiracleCureTM vs OldBoring, 200 participants were recruited and split into two groups at random, with exactly 100 in each group. In the group that took MiracleCureTM, 20 patients recovered. In the group that took OldBoring, 60 recovered.
Draw out a 2x2 table as shown above and fill in the numbers from this trial in place of a, b, c, d.
Think of at least 3 different ways to summarise the data that would help you explain it quickly to someone else. Use the table you have drawn to calculate your results in each case.
When you are finished, click the "Our thoughts" link below for some reflections on this exercise.