Table 1.

Proportions of exposed/unexposed persons and outcomes (2 × 2 table)

		Status of disease/death from disease
		yes (j = 1)	no (j = 0)	∑
Exposure	exposed (i = 1)	π11	π10	π1•
	unexposed (i = 0)	π01	π00	π0•
	∑	π•1	π•0	1