|
|
|
front |1 |2 |3 |4 |5 |6 |7 |8 |9 |10 |11 |12 |13 |14 |15 |16 |17 |18 |19 |20 |21 |22 |23 |review |
 |
Pairs of cases and controls that agree, they do not give any information on the risk associated with exposure. This information is given by pairs where exposure between cases and controls,differ. |