Table 2.
2 ×2 contingency table for a drug-ADR pair
| Reports with ADR | Reports without ADR | Total | |
| Reports with drug | a | b | a+b |
| Reports without drug | c | d | c+d |
| Total | a+c | b+d | a + b + c + d |
2 ×2 contingency table for a drug-ADR pair
| Reports with ADR | Reports without ADR | Total | |
| Reports with drug | a | b | a+b |
| Reports without drug | c | d | c+d |
| Total | a+c | b+d | a + b + c + d |