Table 4 Illustration of the effect of collapsing exposure categories
X1=1 | X1=2 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
\( {\overset{\sim }{X}}_2 \) | Diseased | Not diseased | Total | RR | \( {\overset{\sim }{X}}_2 \) | Diseased | Not diseased | Total | RR |
1 | 50 | 650 | 700 | 1.00 | 1 | 25 | 275 | 300 | 1.00 |
2 | 50 | 250 | 300 | 2.33 | 2 | 125 | 575 | 700 | 2.14 |