Table 1

Prognostic factor	Group 1	Group 2
Sex
Male	3	5
Female	5	3
Age band
21-30	4	4
31-40	2	3
41-50	2	1
Risk factor
High	4	5
Low	4	3

If the 17^th subject has factors Male, 31-40, High in Group 1:
Total in group 1, 3+2+4=9.
Total in group 2, 5+3+5=13.
17^th subject is registered because 9≤13

Table 1: An example of how the dynamic registration works in a setting of an observational study.