Table 2 The measures of proportionality used for the identification of ADRs

PRR

$\frac{a/\left(a+b\right)}{c/\left(c+b\right)}$

PRR − 1.96δ > 1

ROR

$\frac{a/c}{b/d}$

ROR − 1.96δ > 1

MHRA

PRR, a, χ²

PRR ≥ 2, a ≥ 3, χ² ≥ 4