Table 1 Two algorithms used for signal detection
Algorithms | Equation | Criteria |
|---|---|---|
ROR | ROR=(a/c)/(b/d) | a ≥ 3, lower limit of 95%CI> 1 |
95%CI = eln (ROR) ± 1.96 (1/a + 1/b + 1/c + 1/d)^0.5 | ||
PRR | PRR = [a/(c + d)]/[c/(a + b)] | a ≥ 3, PRR ≥ 2, χ2 ≥ 4 |
χ2 = [(ad–bc)^2](a + b + c + d)/[(a + b) (c + d) (a + c) (b + d)] |