Table 1.

Hypothetical randomised trial in which 12 people are randomly assigned to one of three treatment durations of aspirin: no aspirin (durA=0), one year (durA=1), two years (durA=2).

Person	durA	Aspirin at start of first year	Dead at end of first year	Aspirin at start of second year	Dead at end of second year
1	0	No	No	No	No
2	0	No	No	No	Yes
3	0	No	No	No	Yes
4	0	No	Yes	-	Yes
5	1	Yes	No	No	No
6	1	Yes	No	No	Yes
7	1	Yes	No	No	Yes
8	1	Yes	Yes	-	Yes
9	2	Yes	No	Yes	No
10	2	Yes	No	Yes	Yes
11	2	Yes	No	Yes	Yes
12	2	Yes	Yes	-	Yes