A 2*2 Contingency Table is used in statistics to organize and
display the frequency of variables. A 2*2 table setup is shown
below:
2 * 2 Contingency Table
Outcome
No outcome
Total
Risk factor
a
b
a+b
No risk factor
c
d
c+d
Total
a+c
b+d
a+b+c+d
Contingency table are constructed by listing all the levels of
one variable as rows in a table and the levels of the other
variables as columns , then finding the joint or cell frequency for
each cell. The cell frequencies are then summed across both rows
and columns.